Introduction Heat injury is a common illness among new conscripts during basic training course in Thailand and heat stroke is a major cause of death. There are a lot of methods to reduce the body temperature of conscripts to prevent heat injury. The conscripts are allowed to take a bath in the evening every day as regular bath during training. Daytime bath is one of the procedures. The objective of this study is to compare the effectiveness between daytime bath and regular bath for heat injury prevention among new conscripts in training unit.

Methods A quasi-experimental study was conducted in 93 new conscripts in training unit. The data of their body temperature before and after daytime bath in the time of 1200 and 0300 pm were collected. The body temperature data after regular bath were collected in the time of 0600 pm. The paired t–test was used to compare the difference between body temperature means before and after daytime bath and ANOVA was used to compare the difference between body temperature means after daytime bath and regular bath.

Results There were 93 conscripts participating in this study with response rate of 100%. The results of the analyses showed that the body temperature after daytime bath is lower than before bath in statistically significant (p<0.05). But, the difference of body temperature between daytime bath and regular bath is not statistically significant. (p>0.05).

Discussion Both regular and daytime bath showed effectiveness in decreasing body temperature. Therefore, daytime bath can be used as additional method to reduce body temperature in the daytime period to prevent heat injury.