Abstract
Sufficient body water is required to sustain thermoregulatory function, thus losses
in total body water (TBW) can challenge the thermoregulatory system. A TBW deficit
≥2% body mass (hypohydration) is recognized as the threshold when thermoregulatory
function becomes measurably altered. Hypohydration may occur from voluntary fluid
restriction, insufficient fluid availability, or thermoregulatory sweating. The secretion
and evaporation of sweat important avenues of body heat loss, and if the water lost
is not replaced, hypohydration will decrease plasma volume and increase plasma osmotic
pressure (hyperosmotic hypovolemia). Both osmotic and/or volume stressors delay the
onset and/or reduce the sensitivity of sweating and blood flow responses. The magnitude
of hypohydration, environmental heat stress, the population and circumstances of interest
will determine the degree, significance and outcome of these thermoregulatory alterations
and their contribution to physiological stress.
Keywords
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Article info
Publication history
Published online: March 01, 2016
Accepted:
February 7,
2016
Received in revised form:
February 4,
2016
Received:
October 21,
2015
Identification
Copyright
Published by Elsevier B.V.
