Sweatology+HW4+MC

(1) Why is sweat like your personal air-conditioner and why is that important? Sweat is like your personal air conditioner because it dissipates the heat generated by the body’s metabolism and to relieve the heat absorbed from miserable summer weather. It’s important because we have little tolerance for even brief overheating: the brain malfunctions with six of seven degrees of fever, and an internal temperature of 110 is often cited as the upper limit compatible with life. (2) The human body can tolerate cooling. How much? Give examples. We can tolerate overcooling, usually recovering from long periods of hypothermia with body temperatures diving 20 or more degrees below normal. Examples are our sweat glands keeping us cool with copious sweat. (3) The human body cannot tolerate over heating. How much? Give examples. The body malfunctions with six or seven degrees of fever, and an internal temperature of 110, barely a dozen degrees above normal. Humidity, exercise, and the temperature climbing into the 90’s are all examples of possible over-heating situations. (4) Why do we think humans evolved sweat glands? Give examples. We think humans evolved sweat glands because without plentiful swat glands keeping us cool with copious sweat, we would still be clad in the thick hair of our ancestors, living largely apelike lives. Examples are that sweat glands evolved as body hair vanished, allowing optimal cooling of the enlarging hominid brain and an active lifestyle even in the blazing sun. (5) Describe some of the variation in the amount of sweat glands. Give examples. Some people have fewer than two million sweat glands; some have as many as four million. Heavy sweaters may have glands five times average size; their big glands are more sensitive to nerve stimuli and make more sweat. (6) What happens during menopause with respect to sweat? Give examples. With menopause the female thermostat becomes notoriously trigger-happy, imagining excess heat where non exists and generating unnecessary sweat. An example is that women run about half a degree higher after ovulation. (7) What happens as we age? Why is that dangerous? Give examples. At the beginning of about 60 both sexes sweat less, even if they are in a good physical condition, and even if they become seriously overheated. It’s dangerous because the statistics during heat waves show that the elderly are at the highest risk of heat stroke. An example is that the elderly can run and be active, but they will never sweat as much as they did when they were younger, but if they do, their bodies overheat because of their blood being so thin, causing a heat stroke. (8) Is clothing good or bad when it comes to sweat? Why? Give examples. Less is not always better because your unprotected skin absorbs so much heat in the environment. An example is that volunteers were sat on wooden boxes in the California desert, some wearing standard olive drab military fatigues, some in light tan summer uniforms, and some “near naked.” The unclothed soldiers sweated about 30 percent more than the others.

(9) Describe what happens during heat acclimation. Give examples. The internal temps climb, they sweat vigorously, lose large quantities of salt in their sweat and feel miserable. But as days pass, they sweat even more, their salt loss diminishes, both skin and internal temps drop, and their endurance improves. An example is that in monkeys exposed to continuous heat and humidity, individual sweat glands more then doubled in volume after only two months. (10) Who is "Adam"? Why is he being used for scientific experimentation? Adam is a mannequin who sweats like a human being and can complain like one too. His slim carbon frame is covered with 120 separate temp—sensing and sweating zones. He was used to help reduce automobile fuel consumption by evaluating ways to limit air. He has helped evaluate clothes for astronauts to wear underneath their spacesuits, and devices to warm injured soldiers.