THE INFLUENCE OF BRIGHT LIGHT EXPOSURE FOR SEVERAL HOURS DURING DAYTIME ON TYMPANIC TEMPERATURE LEVEL AT SWEATING ONSET

The present study aimed to discover whether the relationship between s weating onset and tympanic temperature (T-ty) could be influenced by b right light (5500 lux, bright) or dim light (150 lux, dim) from 09:00 h to 13:30 h. Four out of five subjects began to sweat at lower Tt, af ter bright than after dim when the ambient temperature increased from 30 degrees C to 35 degrees C. Melatonin excreting rate in urine was si gnificantly higher in bright than in dim at 13:00 h. It was concluded that bright light exposure during the daytime could change the thresho ld for local sweating. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.