[Changes in core temperature during snow shoveling among healthy young males in heavy-snowfall area of Chugoku region in Japan].

Objectives: There are several recommendations on the prevention of hypothermia during snow shoveling. However, there seemed to be insufficient evidence supporting these recommendations because they are not based on data from actual snow shoveling research. The purpose of this study was to investigate changes in brain temperature (tympanic temperature) and visceral temperature (rectal temperature) during snow shoveling among healthy young males. Methods: Eight healthy young males (age, 23.6 ± 2.4 years; weight, 69.7 ± 6.1 kg; height, 172.8 ± 7.3 cm) performed snow shoveling with an ordinary-size shovel for 15 min at their own pace in a rural snowfall area in December, 2009. Rectal temperature (Tre) and tympanic temperature (Tty) were measured 5 times (at rest, 5th (Ex5), 10th (Ex10), and 15th (Ex15) minute of snow shoveling; and 5th (Rec5) minute of recovery phase). The room temperature was 18.6 ± 0.7°C and the atmospheric temperature was 3.8 ± 2.6°C. Results: Tre continued to increase from at rest to Ex15. Tre at Ex15 (37.7 ± 0.3°C) was significantly higher (p < 0.05) than that at rest (37.2 ± 0.3°C). Tty at rest (36.7 ± 0.2°C) and Tty at Ex5 (36.6 ± 0.3°C) decreased significantly (p < 0.05) at Ex10 (36.2 ± 0.6°C). A significant negative correlation between changes in Tre and Tty were observed during snow shoveling (r = -0.49, p < 0.05). Conclusion: Discrepancy between changes in brain temperature (tympanic temperature) and visceral temperature (rectal temperature) should be taken into consideration in the prevention of disease development during snow shoveling in a cold environment.