If calcium levels are low and PTH levels are normal or low, then PTH is not responding properly and the person tested probably has hypoparathyroidism. Hypoparathyroidism is a failure of the parathyroid glands to produce sufficient PTH.
Heat exhaustion definition and facts. 1  Heat exhaustion is one part of the spectrum of heat-related illnesses that begin with heat cramps, progresses to heat exhaustion, and finally to heat stroke.  The body cools itself by sweating and allowing that sweat to evaporate.
Heat exhaustion occurs as a consequence of disruption of the body's own system of thermoregulation, the means by which it adjusts temperature. Sweating is the principal means through which the body cools itself down, but diverting blood from other regions toward the skin also serves this purpose.