Effectiveness of a Head Wash Cooling Protocol Using Non‐Refrigerated Water in Reducing Heat Stress

Abstract

Health, Japan-Envisioning a cooling method and aiming at maximum feasibility and simplicity, we designed an experimental intervention-control study based on non-refrigerated water usage, consisting of pouring 2 l of 23.0°C water simultaneously on head and hands for one minute, after every 20 min of exertion. The subjects were 11 fit male individuals between 19 and 26 yr old. Each individual participated in one control and one intervention measurement in a climatic chamber at 35°C and 60% humidity (31.5°C WBGT) on different days. Heart rate, rectal, esophageal, skin and external ear canal temperatures were monitored constantly. Each experiment consisted of 10 min of basal recording followed by 3 intervals of 20 min of cycling and 15 min of rest. Stabilometry and visual reaction time tests were performed before and after each resting period. A questionnaire evaluating equilibrium, concentration, alertness and tiredness was administered at the beginning and at the end of every experiment. Paired t-test analysis revealed significant improvements in subjective parameters (all p<0.05), as well as skin (p<0.05), external ear canal (p<0.01) and esophageal (p<0.05) temperatures during the rest periods. Repeated measurement analysis of variance revealed significant cooling in all the aforementioned temperatures except the esophageal temperature (p=0.28). Other parameters were not significantly different. Our findings indicate that this method has subjective and physiologic positive effects, and thus can be used as a complementary low cost method to cool subjects safely. (J Occup Health 2008; 50: 251-261)

Physiological And Perceived Effects Of Head Cooling During Simulated Firefighting Activity

“…The observed competitiveness that developed between firefighters may also contribute to improved test performance. One study showed improved processing speed in the Headminders Cognitive Stability Index (CSI) test in participants who were 3.27% dehydrated on average 50. The improved processing speed found in that study may be similar to the reduced interference score (increased number of conflicting colors stated) of the firefighters in the current study; however, the firefighters in the current study were dehydrated to a lesser degree, demonstrating less than one percent dehydration on average.…”

“…This had no significant effect on reducing rectal temperature or HR. 50 However, head wash cooling did significantly improve the partcipants' perception of alertness, concentration capacity, equilibrium, and tiredness. 50 Simmons et al investigated the effect of head and neck cooling on high core temperature.…”

“…50 However, head wash cooling did significantly improve the partcipants' perception of alertness, concentration capacity, equilibrium, and tiredness. 50 Simmons et al investigated the effect of head and neck cooling on high core temperature. Subjects were passively heated in a 45°C/50% relative humidity environmental chamber until their rectal temperature increased 1°C.…”

“…Most have found no significant reduction in rectal temperature. [24][25][26]50 Fujii et al explored the effects of pouring 2 liters of non-refrigerated water over the head and hands. Participants cycled for 20 minutes in a 35°C/60% relative humidity environmental chamber then had 15 minutes of rest.…”

Untitled

“…Some authors describe heat exhaustion as an early stage of, or a warning for impending heat stroke [2;8]. Other authors put both heat exhaustion and heat stroke at the same category [9], or suggest some overlap between the two disorders. Heat exhaustion is mostly ill-defined in literature, with absent diagnostic criteria, and inconsistent recommendations of management [10].…”