Scrotal cooling increases rectal temperature in man

The aim of this study was to evaluate the effect of scrotal cooling on rectal temperature in man. Pilot studies suggested that immersing the scrotum in a 30 degrees C water bath increased rectal temperature, but immersing the scrotum in a 0 degree C water bath did not. Six healthy young men immersed their scrotums in a 35 degrees C water bath for 11 min followed by 21 min at 30 degrees C. Rectal temperature rose by 0.38 +/- 0.04 degrees C (P < 0.01) in response to the 30 degrees C water bath. Repetition of the study by immersing the hands instead of the scrotum in the water bath had no effect on rectal temperature. The scrotum appears to play a role in human temperature regulation.