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O'Connor FK, Meade RD, Notley SR, Ioannou LG, Flouris AD, Kenny GP. Agreement between measured and self-reported physiological strain in males and females during simulated occupational heat stress. Am J Ind Med 2024; 67:466-473. [PMID: 38493300 DOI: 10.1002/ajim.23580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/26/2024] [Accepted: 02/23/2024] [Indexed: 03/18/2024]
Abstract
RATIONALE Monitoring physiological strain is recommended to safeguard workers during heat exposure, but is logistically challenging. The perceptual strain index (PeSI) is a subjective estimate thought to reflect the physiological strain index (PSI) that requires no physiological monitoring. However, sex is known to influence perceptions of heat stress, potentially limiting the utility of the PeSI. OBJECTIVES The objective of this study was to assess whether sex modifies the relationship between PeSI and PSI. METHODS Thirty-four adults (15 females) walked on a treadmill (moderate intensity; ~200 W/m2) for 180 min or until termination (volitional fatigue, rectal temperature ≥39.5°C) in 16°C, 24°C, 28°C, and 32°C wet-bulb globe temperatures. Rectal temperature and heart rate were recorded to calculate PSI (0-10 scale). Rating of perceived exertion and thermal sensation were recorded to calculate PeSI (0-10 scale). Relationships between PSI and PeSI were evaluated via linear mixed models. Mean bias (95% limits of agreement [LoA]) between PSI and PeSI was assessed via Bland-Altman analysis. Mean absolute error between measures was calculated by summing absolute errors between the PeSI and the PSI and dividing by the sample size. FINDINGS PSI increased with PeSI (p < 0.01) but the slope of this relation was not different between males and females (p = 0.83). Mean bias between PSI and PeSI was small (-0.4 points), but the 95% LoA (-3.5 to 2.7 points) and mean absolute error were wide (1.3 points). IMPACT Our findings indicate that sex does not appreciably impact the agreement between the PeSI and PSI during simulated occupational heat stress. The PeSI is not a suitable surrogate for the PSI in either male or female workers.
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Affiliation(s)
- Fergus K O'Connor
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Robert D Meade
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Sean R Notley
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Leonidas G Ioannou
- Department of Automatics, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Andreas D Flouris
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Karies, Trikala, Greece
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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2
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Yang J, Wei Y, An Q, Yuan M. Association between physiological and perceptual heat strain while wearing stab-resistant body armor. J Therm Biol 2023; 114:103567. [PMID: 37209632 DOI: 10.1016/j.jtherbio.2023.103567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 02/25/2023] [Accepted: 04/05/2023] [Indexed: 05/22/2023]
Abstract
In this study, we explored the association between physiological and perceptual heat strain while wearing stab-resistant body armor (SRBA). Human trials were performed on ten participants in warm and hot environments. Physiological responses (core temperature, skin temperature, and heart rate), and perceptual responses (thermal sensation vote, thermal comfort vote, restriction of perceived exertion (RPE), wetness of skin, and wetness of clothing) were recorded throughout the trials, and subsequently, the physiological strain index (PSI), and perceptual strain index (PeSI) were calculated. The results indicated that the PeSI showed a significant moderate association with the PSI, and was capable of predicting PSI for low (PSI = 3) and high (PSI = 7) levels of physiological strain with the areas under the curves of 0.80 and 0.64, respectively. Moreover, Bland-Altman analysis indicated that the majority of the PSI ranged within the 95% confidence interval, and the mean difference between PSI and PeSI was 0.14 ± 2.02 with the lower 95% limit and upper 95% limit being -3.82 to 4.10, respectively. Therefore, the subjective responses could be used as an indicator for predicting physiological strain while wearing SRBA. This study could provide fundamental knowledge for the usage of SRBA, and the development of physiological heat strain assessment.
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Affiliation(s)
- Jie Yang
- College of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an, 710054, China
| | - Yuchen Wei
- State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing, 100081, China.
| | - Qiqi An
- College of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an, 710054, China
| | - Mengqi Yuan
- State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing, 100081, China
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Yang J, Zhang Y, Huang Y, Chen W. Effects of liquid cooling garment on physiological and psychological strain of firefighter in hot and warm environments. J Therm Biol 2023; 112:103487. [PMID: 36796928 DOI: 10.1016/j.jtherbio.2023.103487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/19/2023] [Accepted: 01/19/2023] [Indexed: 02/04/2023]
Abstract
This study aimed to explore the effects of a liquid cooling garment on the physiological and psychological strains of firefighters. Twelve participants wearing firefighting protective equipment with the liquid cooling garment (LCG group) and without the liquid cooling garment (CON group) were recruited to conduct human trials in a climate chamber. During the trials, physiological parameters (mean skin temperature (Tsk), core temperature (Tc), and heart rate (HR)) and psychological parameters (thermal sensation vote (TSV), thermal comfort vote (TCV), and rating of perceived exertion (RPE)) were measured continuously. The heat storage, sweating loss, physiological strain index (PSI), and perceptual strain index (PeSI) were calculated. The results indicated that the liquid cooling garment decreased the mean skin temperature (maximum value of 0.62 °C), scapula skin temperature (maximum value of 1.90 °C), sweating loss (26%), and PSI (0.95 scales) with a significant difference (p < 0.05) at some time points when compared with the CON group. Moreover, the liquid cooling garment had little influence (p > 0.05) on core temperature, heart rate, TSV, TCV, RPE, and PeSI. The association analysis indicated that psychological strain had the potential to predict physiological heat strain with an R2 value of 0.86 between the PeSI and PSI. This study offers insights into the evaluation of cooling system performance, the design of next-generation cooling systems, and the improvement of firefighters' benefits.
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Affiliation(s)
- Jie Yang
- College of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an, 710054, China
| | - Yiwen Zhang
- College of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an, 710054, China
| | - Yiming Huang
- School of Energy and Building Environment, Guilin University of Aerospace Technology, Guilin, 541004, China
| | - Weiwang Chen
- Key Laboratory of Civil Aviation Thermal Hazards Prevention and Emergency Response, Civil Aviation University of China, Tianjin, 300300, China.
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Clusiault D, Avery T, Stephens A, Vigna C, Fischer SL. Scoping review on the state of the integration of human physiological responses to evaluating heat-stress. APPLIED ERGONOMICS 2022; 101:103704. [PMID: 35139444 DOI: 10.1016/j.apergo.2022.103704] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/26/2022] [Accepted: 01/30/2022] [Indexed: 06/14/2023]
Abstract
OBJECTIVES To determine the state of the literature on assessing heat-stress using physiological parameters. To provide recommendations to the nuclear industry regarding worker heat-stress management practices. METHODS A scoping review identified relevant articles. A search strategy was developed based on a research question concepts. Identified records were screened with inclusion-exclusion criteria. Included articles underwent data extraction using a qualitative data charting method. A thematic analysis and frequency counts were performed. RESULTS 1687 articles were identified through four databases. The final inclusion consisted of 34 studies. Articles were classified by determinants of heat exposure risks: core body temperature (direct and indirect), scoring scale including core body temperature, scoring scale including human perception, and others. Heart rate and rectal temperature were the two most utilized physiological measurements. CONCLUSION A significant amount of literature examined estimation of core temperature using non-invasive methods, sometimes integrated into wearables. Heat-stress management practices could include perceptual measures to better evaluate heat-strain.
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Affiliation(s)
- David Clusiault
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON, Canada
| | | | - Allison Stephens
- Advanced Ergonomics Studies, Fanshawe College, London, ON, Canada
| | - Chris Vigna
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON, Canada
| | - Steven L Fischer
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON, Canada.
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Yazdanirad S, Foroushani AR, Monazzam MR, Dehghan H, Golbabaei F. Development of an observational - perceptual heat strain risk assessment (OPHSRA) index and its validation. BMC Public Health 2021; 21:2323. [PMID: 34969389 PMCID: PMC8717656 DOI: 10.1186/s12889-021-12325-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 11/26/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The thermal strain can be measured using subjective methods without the use of sensitive equipment. The purpose of the present study was the development and validation of an observational - perceptual heat strain risk assessment (OPHSRA) method. METHODS This cross-sectional study, in 2019, was performed. At first, an observational-perceptual questionnaire was designed using effective items in producing heat strain. Then, the reliability and validity of the questionnaire were examined. Later, 201 male workers were asked to perform the routine tasks for 90 min under various climatic conditions after resting in a cool room. At the end of the activity, the tympanic temperature of the subjects was accurately measured. Also, the designed questionnaire was completed by researchers and participants. Then, the effect coefficients of the items were calculated and used for developing the novel index. At final, the index validity was investigated. RESULTS The values of the content validity ratio (CVR), content validity index (CVI), and Cronbach's coefficient alpha (α) of the designed questionnaire with 16 questions were equal to 0.793, 0.913, and 0.910, respectively. The results indicated that environmental, job, administrative, and clothing items assessed by the questionnaire with the coefficients of 0.860, 0.658, 0.783, and 0.566 had significant effects on the thermal strain, respectively. These coefficients were exploited to develop the index. The result revealed that the OPHSRA index justified 69% of the variations of the tympanic temperature (R2 = 0.69). CONCLUSION The novel index developed by the questionnaire had an acceptable validity. Therefore, this index can be used for estimating the risk of thermal strain in a variety of thermal conditions.
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Affiliation(s)
- Saeid Yazdanirad
- School of Health, Shahrekord University of Medical Sciences, Shahrekord, Iran.,Modeling in Health Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Abbas Rahimi Foroushani
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Monazzam
- Department of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Habibollah Dehghan
- Department of Occupational Health Engineering, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Farideh Golbabaei
- Department of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
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Weiner CM, Kazman JB, Abraham PA, Deuster PA. Perceptual strain in a compensable hot environment: Accuracy and clinical correlates. J Therm Biol 2021; 100:102863. [PMID: 34503767 DOI: 10.1016/j.jtherbio.2021.102863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 10/22/2022]
Abstract
Heat strain monitoring indexes are important to prevent exertional heat illness (EHI) and uncover risk factors. Two indexes are the Physiological Strain Index (PSI) and a subjective PSI analogue, the Perceptual Strain Index (PeSI). The PeSI is a feasible alternative to PSI in field conditions, although the validity has been variable in previous research. However, the PeSI has been rarely examined at a low heat strain with compensable heat stress, such as during a heat tolerance test (HTT). This study evaluated the discrepancy between the maximal PeSI and maximal PSI achieved during a HTT and determined their association with EHI risk factors, including history of EHI, percent body fat (%BF), relative VO2max, fatigue and sleep status (n = 121; 47 without prior EHI, 74 with prior EHI). The PSI was calculated using the change in rectal temperature (Tre) and heart rate (HR) and PeSI was calculated based on the formula containing thermal sensation (TS), a Tre analogue, and rate of perceived exertion (RPE), a HR analogue. Significant associations were identified between PSI and PeSI and between PSIHR and PeSIHR in the total sample and between PSI and PeSI in the EHI group. Bland-Altman analyses indicated PeSI underestimated PSI in the total sample, PSIHR was greater than PeSIHR, and that PSIcore and PeSIcore were not significantly different, but values varied widely at different heat strains. This indicates the use of RPE underestimates HR and that the accuracy of TS to predict Tre may be subpar. This study also demonstrated that participants with higher %BF have a decreased perception of heat strain and that post-fatigue, sleep status and a prior EHI may increase the perception of heat strain. Overall, these results suggest that PeSI is a poor surrogate for PSI in a compensable heat stress environment at low heat strain.
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Affiliation(s)
- Cynthia M Weiner
- Consortium for Health and Military Performance, Department of Military & Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, USA
| | - Josh B Kazman
- Consortium for Health and Military Performance, Department of Military & Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, USA.
| | - Preetha A Abraham
- Consortium for Health and Military Performance, Department of Military & Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, USA
| | - Patricia A Deuster
- Consortium for Health and Military Performance, Department of Military & Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, USA
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Martín-Rodríguez F, Sanz-García A, López-Izquierdo R, Delgado Benito JF, Martín-Conty JL, Castro Villamor MA, Ortega GJ. Predicting Health Care Workers' Tolerance of Personal Protective Equipment: An Observational Simulation Study. Clin Simul Nurs 2020; 47:65-72. [PMID: 32895609 PMCID: PMC7467653 DOI: 10.1016/j.ecns.2020.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND More recently, due to the coronavirus disease 2019 pandemic, health care workers have to deal with clinical situations wearing personal protective equipment (PPE); however, there is a question of whether everybody will tolerate PPE equally. The main objective of this study was to develop a risk model to predict whether health care workers will tolerate wearing PPE, C category, 4B/5B/6B type, during a 30-minute simulation. METHODS A nonexperimental simulation study was conducted at the Advanced Simulation Center, Faculty of Medicine, Valladolid University (Spain) from April 3rd to 28th, 2017. Health care students and professionals were equipped with PPE and performed a 30-minute simulation. Anthropometric, physiological, and analytical variables and anxiety levels were measured before and after simulation. A scoring model was constructed. RESULTS Ninety-six volunteers participated in the study. Half the sample presented metabolic fatigue in the 20 minutes after finishing the simulation. The predictive model included female sex, height, muscle and bone mass, and moderate level of physical activity. The validity of the main model using all the variables presented an area under the curve of 0.86 (95% confidence interval: 0.786-0.935), and the validity of the model had an area under the curve of 0.725 (95% confidence interval: 0.559-0.89). CONCLUSIONS Decision-making in biohazard incidents is a challenge for emergency team leaders. Knowledge of health care workers' physiological tolerance of PPE could improve their performance.
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Affiliation(s)
- Francisco Martín-Rodríguez
- Advanced Clinical Simulation Center, Faculty of Medicine, Valladolid University, 47005 Valladolid, Spain
| | - Ancor Sanz-García
- Data Analysis Unit, Health Research Institute, Hospital de la Princesa, 28006 Madrid, Spain
| | - Raúl López-Izquierdo
- Emergency Department, Hospital Universitario Rio Hortega, 47012 Valladolid, Spain
| | | | - José L Martín-Conty
- Faculty of Health Sciences, Universidad de Castilla la Mancha, 45600 Talavera de la Reina, Toledo, Spain
| | - Miguel A Castro Villamor
- Advanced Clinical Simulation Center, Faculty of Medicine, Valladolid University, 47005 Valladolid, Spain
| | - Guillermo J Ortega
- Data Analysis Unit, Health Research Institute, Hospital de la Princesa, 28006 Madrid, Spain
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Notley SR, Flouris AD, Kenny GP. On the use of wearable physiological monitors to assess heat strain during occupational heat stress. Appl Physiol Nutr Metab 2018; 43:869-881. [DOI: 10.1139/apnm-2018-0173] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Workers in many industries are required to perform arduous work in high heat-stress conditions, which can lead to rapid increases in body temperature that elevate the risk of heat-related illness and even death. Traditionally, effort to mitigate work-related heat injury has been directed toward the assessment of environmental heat stress (e.g., wet-bulb globe temperature), rather than toward the associated physiological strain responses (e.g., heart rate and skin and core temperatures). However, because a worker’s physiological response to a given heat stress is modified independently by inter-individual factors (e.g., age, sex, chronic disease, others) and intra-individual factors both within (e.g., medication use, fitness, acclimation and hydration state, others) and beyond (e.g., shift duration, illness, others) the worker’s control, it becomes challenging to protect workers on an individual basis from heat-related injury without assessing those physiological responses. Recent advancements in wearable technology have made it possible to monitor one or more physiological indices of heat strain. Nonetheless, information on the utility of the wearable systems available for assessing occupational heat strain is unavailable. This communication is therefore directed toward identifying the physiological indices of heat strain that may be quantified in the workplace and evaluating the wearable monitoring systems available for assessing those responses. Finally, emphasis is placed on the barriers associated with implementing these devices to assist in mitigating work-related heat injury. This information is fundamental for protecting worker health and could also be utilized to prevent heat illnesses in vulnerable people during leisure or athletic activities.
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Affiliation(s)
- Sean R. Notley
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Andreas D. Flouris
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Functional Architecture of Mammals in their Environment (FAME) Laboratory, Department of Exercise Science, University of Thessaly, Trikala, Greece
| | - Glen P. Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
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von Heimburg E, Sandsund M, Rangul TP, Reinertsen RE. Physiological and perceptual strain of firefighters during graded exercise to exhaustion at 40 and 10 °C. INTERNATIONAL JOURNAL OF OCCUPATIONAL SAFETY AND ERGONOMICS 2017; 25:412-422. [PMID: 28976263 DOI: 10.1080/10803548.2017.1381468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Purpose. To study whether perceptual identification should be included as a measure to evaluate physiological stress. Methods. Physiological variables oxygen uptake (VO2), ventilation, heart rate, blood lactate concentration, rectal temperature (Trec) and mean skin temperature, and perceptual variables rate of perceived exertion, thermal sensation and time to exhaustion, were measured at submaximal and maximal intensities during graded exercise on a treadmill to exhaustion in 12 firefighters wearing protective clothing and extra mass at 40 and 10 °C. Physiological strain index (PhSI) and perceptual strain index (PeSI) were calculated. Results. Apart from Trec, all physiological and perceptual variables were higher at submaximal intensities of 40 °C. Time to exhaustion was 16% shorter and the corresponding VO2 was reduced by 7% in the heat. A high correlation (r = 89) between PhSI and PeSI was found at both temperatures. PeSI scores were equal to PhSI at both ambient temperatures, except at the two highest intensities in the heat, where PeSI was higher. Conclusions. These findings support use of perceptual identification to evaluate physiological stress. However, at very high intensities under hot conditions the perceptual strain was estimated higher than the physiological strain. More precise indexes are needed to include perceptual measures in safety standard.
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Affiliation(s)
| | - Mariann Sandsund
- b Department of Health Research , SINTEF Technology and Society , Norway
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10
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Walker A, Rattray B, Brearley M. Perception or reality: Can thermal perceptions inform management of firefighters in the heat? JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2017; 14:306-312. [PMID: 27791486 DOI: 10.1080/15459624.2016.1240871] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Accurately assessing the physiological status of firefighters during work in the heat is critical to ensuring their safety. Evaluating core temperatures (Tc) in the field is problematic due to cost and limitations in technology and accuracy. As such, fire services rely on individual perceptions of wellbeing. The present study aimed to establish whether perceptual responses measured using the perceptual strain index (PeSI), calculated from rate of perceived exertion (RPE) and thermal sensation (TS), could reliably predict the physiological strain (PSI) encountered by experienced firefighters working in a hot environment. We conducted two firefighting simulations (set-pace and self-paced) in a purposefully built heat chamber (100 ± 5°C) comprised of two 20-min periods separated by a 10-min recovery outside the chamber. Physiological strain was measured via heart rate (HR) and gastrointestinal temperature (Tgi) and compared with PeSI at 5-min intervals. To evaluate the predictive ability of the PeSI for PSI, mean differences and the 95% limits of agreement (LOA) were established, along with correlation coefficients at each 5-min interval. Moderately significant correlations occurred in the second work bout of the self-paced trial only (10 min: r = 0.335, 15 min: r = 0.498, 20 min r = 0.439) with no other correlations observed at any other time during either trial or during the rest periods. Bland-Altman analysis revealed mean differences of -0.74 ± 2.70 (self-paced) and +0.04 ± 2.04 (set-paced) between PeSI and PSI with the 95% LOA being -4.77 to 3.28 (self-paced) and -4.01 to 2.01 (set-paced). The wide LOA and lack of correlations observed between perceptual and physiological strain in both self-paced and set-paced work trials indicate that PeSI is not sufficiently reliable as a sole measure of wellbeing for firefighters working in the heat. Hence, we recommend that fire services prioritise the development of reliable and effective monitoring tools for use in the field.
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Affiliation(s)
- Anthony Walker
- a University of Canberra Research Institute for Sport and Exercise, University of Canberra , Bruce , ACT , Australia
| | - Ben Rattray
- a University of Canberra Research Institute for Sport and Exercise, University of Canberra , Bruce , ACT , Australia
- b Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra , Bruce , ACT , Australia
| | - Matt Brearley
- c National Critical Care and Trauma Response Centre , Darwin , Northern Territory , Australia
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Bach AJE, Costello JT, Borg DN, Stewart IB. The Pandolf load carriage equation is a poor predictor of metabolic rate while wearing explosive ordnance disposal protective clothing. ERGONOMICS 2017; 60:430-438. [PMID: 27110873 DOI: 10.1080/00140139.2016.1173233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 03/25/2016] [Indexed: 06/05/2023]
Abstract
This investigation aimed to quantify metabolic rate when wearing an explosive ordnance disposal (EOD) ensemble (~33kg) during standing and locomotion; and determine whether the Pandolf load carriage equation accurately predicts metabolic rate when wearing an EOD ensemble during standing and locomotion. Ten males completed 8 trials with metabolic rate measured through indirect calorimetry. Walking in EOD at 2.5, 4.0 and 5.5km·h-1 was significantly (p < 0.05) greater than matched trials without the EOD ensemble by 49% (127W), 65% (213W) and 78% (345W), respectively. Mean bias (95% limits of agreement) between predicted and measured metabolism during standing, 2.5, 4 and 5.5km·h-1 were 47W (19 to 75W); -111W (-172 to -49W); -122W (-189 to -54W) and -158W (-245 to -72W), respectively. The Pandolf equation significantly underestimated measured metabolic rate during locomotion. These findings have practical implications for EOD technicians during training and operation and should be considered when developing maximum workload duration models and work-rest schedules. Practitioner Summary: Using a rigorous methodological design we quantified metabolic rate of wearing EOD clothing during locomotion. For the first time we demonstrated that metabolic rate when wearing this ensemble is greater than that predicted by the Pandolf equation. These original findings have significant implications for EOD training and operation.
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Affiliation(s)
- Aaron J E Bach
- a School of Exercise and Nutrition Sciences and Institute of Health and Biomedical Innovation , Queensland University of Technology , Brisbane , Australia
| | - Joseph T Costello
- a School of Exercise and Nutrition Sciences and Institute of Health and Biomedical Innovation , Queensland University of Technology , Brisbane , Australia
- b Extreme Environments Laboratory, Department of Sport and Exercise Science , University of Portsmouth , Portsmouth , UK
| | - David N Borg
- a School of Exercise and Nutrition Sciences and Institute of Health and Biomedical Innovation , Queensland University of Technology , Brisbane , Australia
| | - Ian B Stewart
- a School of Exercise and Nutrition Sciences and Institute of Health and Biomedical Innovation , Queensland University of Technology , Brisbane , Australia
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12
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Borg DN, Costello JT, Bach AJ, Stewart IB. Perceived exertion is as effective as the perceptual strain index in predicting physiological strain when wearing personal protective clothing. Physiol Behav 2016; 169:216-223. [PMID: 27939428 DOI: 10.1016/j.physbeh.2016.12.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 12/05/2016] [Accepted: 12/05/2016] [Indexed: 11/20/2022]
Abstract
OBJECTIVE The perceptual strain index (PeSI) has been shown to overcome the limitations associated with the assessment of the physiological strain index (PSI), primarily the need to obtain a core body temperature measurement. The PeSI uses the subjective scales of thermal sensation and perceived exertion (RPE) to provide surrogate measures of core temperature and heart rate, respectively. Unfortunately, thermal sensation has shown large variability in providing an estimation of core body temperature. Therefore, the primary aim of this study was to determine if thermal comfort improved the ability of the PeSI to predict the PSI during exertional-heat stress. METHODS Eighteen healthy males (age: 23.5years; body mass: 79.4kg; maximal aerobic capacity: 57.2ml·kg-1·min-1) wore four different chemical/biological protective garments while walking on treadmill at a low (<325W) or moderate (326-499W) metabolic workload in environmental conditions equivalent to wet bulb globe temperatures 21, 30 or 37°C. Trials were terminated when heart rate exceeded 90% of maximum, when core body temperature reached 39°C, at 120min or due to volitional fatigue. Core body temperature, heart rate, thermal sensation, thermal comfort and RPE were recorded at 15min intervals and at termination. Multiple statistical methods were used to determine the most accurate perceptual predictor. RESULTS Significant moderate relationships were observed between the PeSI (r=0.74; p<0.001), the modified PeSI (r=0.73; p<0.001) and unexpectedly RPE (r=0.71; p<0.001) with the PSI, respectively. The PeSI (mean bias: -0.8±1.5 based on a 0-10 scale; area under the curve: 0.887), modified PeSI (mean bias: -0.5±1.4 based on 0-10 scale; area under the curve: 0.886) and RPE (mean bias: -0.7±1.4 based on a 0-10 scale; area under the curve: 0.883) displayed similar predictive performance when participants experienced high-to-very high levels of physiological strain. CONCLUSIONS Modifying the PeSI did not improve the subjective prediction of physiological strain. However, RPE provided an equally accurate prediction of physiological strain, particularly when high-to-very high levels of strain were observed. Therefore, given its predictive performance and user-friendliness, the evidence suggests that RPE in isolation is a practical and cost-effective tool able to estimate physiological strain during exertional-heat stress under these work conditions.
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Affiliation(s)
- David N Borg
- Institute of Health and Biomedical Innovation, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane 4059, Queensland, Australia.
| | - Joseph T Costello
- Extreme Environments Laboratory, Department of Sport and Exercise Science, University of Portsmouth, Portsmouth PO1 2ER, United Kingdom
| | - Aaron J Bach
- Institute of Health and Biomedical Innovation, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane 4059, Queensland, Australia
| | - Ian B Stewart
- Institute of Health and Biomedical Innovation, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane 4059, Queensland, Australia
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Pokora I, Żebrowska A. Application of A Physiological Strain Index in Evaluating Responses to Exercise Stress - A Comparison Between Endurance and High Intensity Intermittent Trained Athletes. J Hum Kinet 2016; 50:103-114. [PMID: 28149347 PMCID: PMC5260640 DOI: 10.1515/hukin-2015-0142] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2016] [Indexed: 11/22/2022] Open
Abstract
The study evaluated differences in response to exercise stress between endurance and
high-intensity intermittent trained athletes in a thermoneutral environment using a
physiological strain index (PSI). Thirty-two subjects participated in a running
exercise under normal (23°C, 50% RH) conditions. The group included nine
endurance trained athletes (middle-distance runners - MD), twelve high-intensity
intermittent trained athletes (soccer players - HIIT) and eleven students who
constituted a control group. The exercise started at a speed of 4
km·h–1 which was increased every 3 min by 2
km·h–1 to volitional exhaustion. The heart rate was
recorded with a heart rate monitor and aural canal temperature was measured using an
aural canal temperature probe. The physiological strain index (PSI) and the
contribution of the circulatory and thermal components to the overall physiological
strain were calculated from the heart rate and aural canal temperature. The
physiological strain index differed between the study and control participants, but
not between the MD and HIIT groups. The physiological strain in response to exercise
stress in a thermoneutral environment was mainly determined based on the circulatory
strain (MD group - 73%, HIIT group – 70%). The contribution of the circulatory
and thermal components to the physiological strain did not differ significantly
between the trained groups (MD and HIIT) despite important differences in
morphological characteristics and training-induced systemic cardiovascular and
thermoregulatory adaptations.
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Affiliation(s)
- Ilona Pokora
- Department of Physiology, the Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
| | - Aleksandra Żebrowska
- Department of Physiology, the Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
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