Wet military uniforms pose low risk of hypothermia while static in mild cold air.

Wet clothing is less insulative than dry clothing and consequently increases heat loss in cold air. Tactical necessity can render removal of wet clothing impossible and/or require Warfighters to remain static to avoid detection, limiting heat production and posing a threat of hypothermia (core temperature <35 °C). This study aimed to characterize body temperatures and evaluate hypothermia risk while statically exposed to 5 °C air wearing three wet military uniforms.

Exercise induced plasma volume expansion lowers cardiovascular strain during 15-km cycling time-trial in acute normobaric hypoxia.

The purpose of our study was to assess the influence of a single high-intensity interval exercise (HIIE) bout in normoxia on plasma volume (PV) and consequent cycling performance in normobaric hypoxia (0.15 FiO2, simulating ~2,500 m). Eight males (VO2peak: 48.

Short-term cocoa bioflavanol supplementation does not improve cold-induced vasodilation in young healthy adults.

Purpose: Cold-induced vasodilation (CIVD) is an oscillatory rise in blood flow to glabrous skin that occurs in cold-exposed extremities. Dietary flavanols increase bioavailable nitric oxide, a proposed mediator of CIVD through active vasodilation and/or withdrawal of sympathetic vascular smooth muscle tone. However, no studies have examined the effects of flavanol intake on extremity skin perfusion during cold exposure.

Sex differences in thermal sensitivity and perception: Implications for behavioral and autonomic thermoregulation.

Temperature sensitive receptors in the skin and deep body enable the detection of the external and internal environment, including the perception of thermal stimuli. Changes in heat balance require autonomic (e.g.

Influences of ovarian hormones on physiological responses to cold in women.

While it is clear that the ovarian hormones estradiol and progesterone have important influences on physiological thermoregulation in women, the influences of these hormones on responses to cold exposure are not well understood. Both heat conservation and heat production must increase to offset heat losses that decrease body temperature in cold ambient conditions. Cutaneous vasoconstriction conserves heat, whereas shivering and non-shivering thermogenesis produce heat - all as part of reflex physiological responses to cold exposure.

Short-term hot water immersion results in substantial thermal strain and partial heat acclimation; comparisons with heat-exercise exposures.

Objective: To examine the effectiveness of hot water immersion (HWI) as a heat acclimation strategy in comparison to time and temperature matched, exercise-heat acclimation (EHA).

Methods: 8 males performed heat stress tests (HST) (45 min of cycling at 50% of VO in 40 °C, 40% RH) before and after heat acclimation sessions. Acclimation sessions were either three consecutive bouts of HWI (40 min of submersion at 40 °C) or EHA (40 min of cycling at 50% VO in 40 °C, 40% RH).