Sudomotor and vasomotor responses to changing environmental temperature.

Abstract

Male subjects clad only in shorts were exposed in a climate chamber to a slowly rising ambient temperature while sweating, cutaneous volume pulses, and skin, tympanic membrane, and oral temperatures were simultaneously recorded. Mean skin temperature was continuously computed electronically. After sweating and vasodilatation had become well established, the copper screen bed on which the subject reclined was rapidly moved from the hot chamber into another, 20–30 C cooler. The onset of neither sweating nor vasodilatation could be accurately correlated with tympanic membrane temperature since the latter was observed to be either increasing, unchanged, or even falling during the period of recruitment. In some experiments, vasodilatation preceded sweating, while in others, it followed. When the subject was rapidly moved from the hot environment to the cold, sweating promptly stopped on all of the test areas, and profound vasoconstriction appeared on the palm. Nonpalmer areas, however, showed little or no immediate change in the amplitude of the volume pulses. Mean skin temperature invariably started to fall, but only by a few tenths of a degree when cessation of sweating and palmar constriction occurred. Tympanic membrane temperature during the same period continued to rise for 1–3 min, and thus seemed unrelated to either vasomotor or sudomotor control under these circumstances. sweating; cutaneous vasomotor responses; cutaneous vasodilatation; cutaneous vasoconstriction; tympanic membrane temperatures; mean skin temperatures; nervous control of sweating; nervous control of cutaneous vascular responses; bradykinin and sweating; bradykinin and vasodilatation Submitted on August 13, 1965