Margaret A. Kolka

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The changes occurring in the esophageal temperature (Tes) thresholds for initiation of heat loss responses as affected by the circadian period and menstrual cycle were studied. Four women exercised at 60% peak Vo2 in 35 degrees C (ambient water vapor pressure 1.73 kPa) for 30 min at 0400 and 1600 during the follicular (F) and luteal (L) phase. Tes, arm(More)
PURPOSE Serious heat illness has received considerable recent attention due to catastrophic heat waves in the United States and Europe, the deaths of high-profile athletes, and military deployments. METHODS This study documents heat illness hospitalizations and deaths for the U.S. Army from 1980 through 2002. Hospitalization data were obtained from the(More)
PURPOSE This study determined whether exercise (30 min)-rest (10 min) cycles alter physiologic tolerance to uncompensable heat stress (UCHS) when outdoors in the desert. In addition, the relationship between core temperature and exhaustion from heat strain previously established in laboratory studies was compared with field studies. METHODS Twelve men(More)
The serotonin system may contribute to reduced human performance when hypohydrated in the heat. This study determined whether branched-chain amino acid (BCAA) supplementation could sustain exercise and cognitive performance in the heat (40 degrees C dry bulb, 20% relative humidity) when hypohydrated by 4% of body mass. Seven heat-acclimated men completed(More)
The effectiveness of intermittent, microclimate cooling for men who worked in US Army chemical protective clothing (modified mission-oriented protective posture level 3; MOPP 3) was examined. The hypothesis was that intermittent cooling on a 2 min on-off schedule using a liquid cooling garment (LCG) covering 72% of the body surface area would reduce heat(More)
The purpose of this study was to test the hypothesis that regulated body temperature is decreased in the preovulatory phase in eumenorrheic women. Six women were studied in both the preovulatory phase (Preov-2; days 9-12), which was 1-2 days before predicted ovulation when 17beta-estradiol (E2) was estimated to peak, and in the follicular phase (F; days(More)
The side effects of chronic pyridostigmine bromide administration were studied in seven male soldiers performing moderate-intensity exercise in a desert environment. A 2-week, double-blind, placebo-controlled crossover design was employed in which pyridostigmine was administered for 7 consecutive days (30 mg orally, t.i.d.). Four hours each day were spent(More)
The effect of 33 h of wakefulness on the control of forearm cutaneous blood flow and forearm sweating during exercise was studied in three men and three women. Subjects exercised for 30 min at 60% peak O2 consumption while seated behind a cycle ergometer (Ta = 35 degrees C, Pw = 1.0 kPa). We measured esophageal temperature (Tes), mean skin temperature, and(More)
The effect of saline and atropine injection (2 mg, im) on eight healthy male subjects before and after heat acclimation was studied while each subject walked on a treadmill (1.34 m X s-1) in a hot-dry environment (ambient temperature = 48.4 degrees C, dew-point temperature = 20.5 degrees C). Partitional calorimetric analysis was done for the periods in(More)