Objective: Heat stroke is still an important health problem in Thai army recruits. The authors aimed to evaluate a new method for preventing heat stroke in the newly army recruits during basic training in May-June 2006, by monitoring the bed time body temperature and body weight.
Material and Method: One thousand one hundred and fifteen recruits from five army units in Lopburi Province, Thailand were enrolled in the present study. Standardized questionnaire was used for data collection including unit information, personal information, environmental information and daily activity information. Bed time body temperature and body weight were recorded daily. Anyone who had a body temperature > 37.8°C or body weight lossing > 10% in 24 h had to stop training until these indicators were normal.
Results: There was no incidence of heat stroke in these army units during this training period. There were 191 recruits who had a body temperature > 37.8°C. The mean duration of the fever was 3.3 + 3.3 days. The incidence of fever was 21.4 per 100 persons-month. There were 30 recruits with the body weight lossing > 10%. The duration of body weight loss was one day. Analyzed by Mixed Model using STATA program, there was statistically significant difference of the body temperature (p < 0.001) but not the body weight (p = 0.644) among the period of time.
Conclusion: This monitoring of the bed time body temperature and body weight seems to be effective for the prevention of the occurrence of heat stroke because there was no case of heat stroke in the present study. However, further large-scale study with a control group should be performed.

Keywords: Heat stroke, Army recruits, Body temperature, Body weight, Prevention