Authors
Katsuura T. Tomioka K. Harada H. Iwanaga K. Kikuchi Y.
Institution
Department of Ergonomics, Chiba University.
Title
Effects of cooling
portions of the head on
human thermoregulatory response.
Source
Applied Human Science. 15(2):67-74, 1996 Mar.
Abstract
Seven healthy young male students participated in this study. Each subject
sat on a chair in an anteroom at 25 degrees C for 30 min and
then entered a climatic chamber, controlled at 40 degrees C
and R.H. 50%, and sat on a chair for 90 min. Cooling of
frontal portion including the region around
the eyes (FC), occipital portion (OC), and temporal portion
(TC) began after 50 min of entering. An experiment without
head cooling (NC) was also made for
the control measurement. Thermal comfort
and thermal sensation were improved by head
cooling, but response was the same
regardless of portion cooled. Although rectal temperature, mean skin
temperature and heart rate showed no significant effect due to
head cooling, forearm skin blood flow
(FBF), sweat rate (SR), and body weight loss (delta Wt) had a tendency to be
depressed. FBF in FC and TC decreased during head
cooling, but that in OC and NC did not change significantly,
while SR in FC was depressed. delta Wt showed total sweating to decrease by
FC and TC, and FC to have greater inhibitory effect on sweating than OC.
Thermal strain was evaluated by the
modified Craig Index (I(s)). I(s) in FC decreased significantly more than in
NC. Cooling of other
portions of the head had
no significant effect on I(s). Cooling of
the frontal portion of the
head may thus be concluded to have the most
effect on thermoregulatory response in a hot environment.
Additional commentby poster:
An interesting experiment for determining temperature sensitivity of the face.