Journal of Applied Physiology, Vol 72, Issue 6 2099-2107, Copyright © 1992 by American Physiological Society
Thermoregulatory, cardiovascular, and psychophysical response to alcohol in men in 40 degrees C water
T. G. Allison and W. E. Reger
Cardiac Center, Wheeling Hospital, West Virginia 26003.
The goals of the study were to test the hypotheses that ethyl alcohol
(ETOH) in low-to-moderate doses would alter thermo-regulation and/or
disrupt the normal relationship between physiological and psychophysical
indexes of heat stress during 40 degrees C water immersion and to
characterize the cardiovascular response to the combined stimuli of heat,
water immersion, and ETOH. Six healthy men underwent three trials of 21 min
of immersion in water at 40.0 +/- 0.1 degrees C after consuming 0, 0.27, or
0.54 g ETOH/kg. Esophageal temperature (Tes) rose by approximately 1.0
degrees C during immersion for each trial. Per unit of Tes rise, changes
during immersion in skin temperature, sweat rate, heart rate, systolic and
diastolic blood pressure, and psychophysical assessments of comfort and
overheating did not differ significantly by trial. Across trials, there was
an apparent threshold for activation of thermoregulatory responses at an
approximately 0.5 degrees C increase in Tes occurring after approximately 9
min of immersion. This threshold was identified psychophysically by
increased ratings of overheating and decreased comfort. Above the
threshold, there was an attenuation of the rate of increase of Tes.
Cardiovascular stress was mild (rate-pressure product approximately 12,000)
and not significantly increased by ETOH. Hypotension and tachycardia when
subjects stood to exit the tub were observed. The data suggest that ETOH at
the doses administered does not affect thermoregulatory, cardiovascular, or
psychophysical indexes of heat stress during 40 degrees C water immersion.
