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 is often the prologue of a heat stroke. It is the milder condition compared to the latter. When one becomes overly dehydrated most especially when he or she engages in a strenuous activity under the heat of the sun, then it is expected that this person is likely to suffer from a heat exhaustion.