Ergonomics of the thermal environment. Analytical determination and interpretation of heat stress using calculation of the predicted heat strain

In pursuit of precision livestock farming, the real-time measurement for heat strain-related data has been more and more valued. Efforts have been made recently to use more sensitive physiological indicators with the hope to better inform decision-making in heat abatement in dairy farms. To get an insight into the early detection of heat strain in dairy cows, the present review focuses on the recent efforts developing early detection methods of heat strain in dairy cows based on body temperatures and respiratory dynamics. For every candidate animal-based indicator, state-of-the-art measurement methods and existing thresholds were summarized. Body surface temperature and respiration rate were concluded to be the best early indicators of heat strain due to their high feasibility of measurement and sensitivity to heat stress. Future studies should customize heat strain thresholds according to different internal and external factors that have an impact on the sensitivity to heat stress. Wearable devices are most promising to achieve real-time measurement in practical dairy farms. Combined with internet of things technologies, a comprehensive strategy based on both animal- and environment-based indicators is expected to increase the precision of early detection of heat strain in dairy cows.

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Standard Guide for Managing Heat Stress and Heat Strain in Foundries

10.1520/e3279 ◽

2021 ◽

Author(s):

Keyword(s):

Heat Stress ◽

Heat Strain

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Heat strain in Royal Navy helicopter aircrew

Journal of The Royal Naval Medical Service ◽

10.1136/jrnms-85-84 ◽

1999 ◽

Vol 85 (2) ◽

pp. 84-109

Author(s):

J R House

Keyword(s):

Protective Clothing ◽

Thermal Environment ◽

Cooling System ◽

Heat Strain ◽

Protective Equipment ◽

Flight Period ◽

Royal Navy ◽

Liquid Cooling ◽

And Performance ◽

Climate Cooling

AbstractA review of the literature on heat strain and aircrew and a questionnaire survey of Royal Navy aircrew have been completed. Aircrew appreciate, some 50% from first hand experience, that heat strain can reduce their operational endurance and performance. They are at greatest risk of developing it in the pre-flight period, especially when wearing Nuclear, Biological, or Chemical (NBC) protective equipment. Several techniques they use to reduce this risk are described. Some may be of particular assistance in the field should air conditioned facilities be unavailable. However, opportunities to improve the thermal environment within the aircraft on the ground and in flight are limited as the heat generated within it and high levels of solar radiation impinging on it severely challenge air conditioning units, themselves constrained by weight and size. Other demands placed on protective clothing offer little potential to increase the rate at which aircrew can lose accumulated heat. It is concluded that an appropriate micro-climate cooling system worn next to the skin may be required to achieve truly significant reductions in heat strain. Research at the Institute of Naval Medicine has identified liquid cooling techniques which may be suitable for aircrew in all but the smallest helicopters.Any views expressed are those of the author and do not necessarily represent those of the Department.

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Comparison of heat strain recovery in different anti-heat stress clothing ensembles after work to exhaustion

Journal of Thermal Biology ◽

10.1016/j.jtherbio.2017.09.004 ◽

2017 ◽

Vol 69 ◽

pp. 311-318

Author(s):

Yijie Zhao ◽

Wen Yi ◽

Albert P.C. Chan ◽

Daniel W.M. Chan

Keyword(s):

Heat Stress ◽

Heat Strain ◽

Strain Recovery

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Thermal status of sheep at pasture in western New South Wales

Australian Journal of Agricultural Research ◽

10.1071/ar9710797 ◽

1971 ◽

Vol 22 (5) ◽

pp. 797 ◽

Cited By ~ 13

Author(s):

GD Brown

Keyword(s):

Heat Stress ◽

Thermal Environment ◽

New South ◽

New South Wales ◽

Skin Surface ◽

High Heat ◽

South Wales ◽

Temperature Telemetry ◽

Thermal Status ◽

Outdoor Environments

The thermal status of three unrestrained rams at pasture was studied for a period of 5 days during March in central western New South Wales. A temperature telemetry system was used to measure rectal temperatures, skin surface and subcutaneous temperatures on the mid back, and subcutaneous temperatures of the scrotum of each ram. Rectal temperatures of 40�C and above were recorded for all rams on each day, the highest recorded being 41 9 4 and 41.6�. Rectal temperatures in excess of 40� were also recorded for extended periods between 6.00 p.m. and midnight. Although respiratory frequencies increased with the increase in environmental heat load during the day, no obvious signs of extreme heat stress were noted at these elevated rectal temperatures, whereas sheep exposed to high heat loads in indoor experiments consistently exhibit heat stress at similar rectal temperatures. Rectal temperatures were generally higher and more variable than those reported by other workers for penned sheep in either indoor or outdoor environments. Subcutaneous scrota1 temperatures were usually lower than those which might be expected to induce sterility. Variations in the temperatures measured have been related to the thermal environment and patterns of behaviour of the sheep.

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