Abstract
A modeling approach is used to study the effectiveness of the Active Cooling (AC) method of hand and forearm immersion in cold water to reduce core temperature following heavy physical activity. A transient multi-node segmental bioheat model based on physiology and accurate mathematical modeling of thermoregulatory functions are used to predict human segmental core and skin temperatures, and arterial blood flow for given metabolic rate and environmental conditions. The validity of the model is confirmed by comparison with published experimental data on core temperature during and after immersion of forearms and hands in cold water. The validated model is used in a case study to enhance understanding of associated body thermal changes and arterial blood flow and AVA mechanisms during AC interventions that alleviate thermal stress in hot environment. The time needed for the core temperature to drop from 38.0°C to 37.0°C is found to be 33 minutes when subject is at rest and is exposed to air cooling at 21°C compared to 15 minutes when hands and forearms are immersed in water at 10°C. The average sensible heat loss during the cooling period associated with immersion of forearms and hands in water at 10°C was found to be 106.2 W compared to 75.9 W for passive air cooling at 21°C. The active cooling was found to be an effective method for accelerating reduction on core temperature and can be used with efficient, localized, and portable cooling devices.
Highlights
Global warming and its implications on the well-being of outdoor workers and high performing athletes caused more attention to be devoted to heat stress in light of the increase in the prospects of living in a warmer world and the need to avoid the productivity loss of workers
The simulation tool is based on: 1) multi-node segmental bioheat model, 2) blood circulation model based on actual arterial tree blood flow, and 3) robust thermoregulatory model of Arterio-Venous Anastomoses (AVA) and Cold Induced Vasodilation (CIVD) mechanisms associated with exposure of hands to cold environment
The hand cooling human thermal tool based on thermal modeling and physiology is validated by comparing simulated body core temperature variation and associated sensible heat loss through hands and forearm with published experimental data
Summary
Global warming and its implications on the well-being of outdoor workers and high performing athletes caused more attention to be devoted to heat stress in light of the increase in the prospects of living in a warmer world and the need to avoid the productivity loss of workers. To improve human endurance and productivity in conditions that cause rise in body temperature, methods for quickly cooling the body are sought to reduce rest periods. People’s feeling of discomfort increases when their thermoregulatory system needs to work harder to maintain thermal neutral state [1]. Means to reduce or delay the state of heat stress and prolong work or activity period have included the use of active and passive personal cooling systems and clothing for improved ventilation in hot humid climates. One of the reported effective methods for decreasing quickly the core temperature in literature is the immersion of hand and fore arm in cold water [2,3,4,5]. The most inexpensive and the simplest method to use is cold water hand immersion where water is Received September 18, 2013; Accepted September 19, 2013; Published September 23, 2013
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
