How does your body cope with heat?

- The human body is in a constant state of fluctuating between generating heat and losing heat. Under normal non-working conditions, the body can be exposed to a wide range of temperatures and still maintain its core temperature within a degree or two of normal. However, when a person's working, exercising, or conducting any increased physical activity, the body generates more internal heat. The body moves this internal heat from its core to the skin by increasing the size of the blood vessels near the surface of the skin so they can carry more blood. This is one reason why your skin can appear red in hot weather. As these blood vessels dilate, the heart has to work harder to push the blood to the surface and fill these enlarged vessels. At the same time, your breathing rate can increase and the body begins to perspire, all in an attempt to keep your core temperature within a range that allows your body to function properly. Your core temperature or core body temperature is the temperature of the body's internal organs and it should remain between 36.5 and 38.5 degrees Celsius. And that's 97.7 and 101.3 degrees Fahrenheit. Now I want to take a minute here to explain the difference between core body temperature and peripheral body temperature. The core temperature is the temperature deep inside your body and peripheral temperature is the temperature at or near the surface level, near your skin. And when you take someone's temperature using an oral thermometer or a thermometer that scans the forehead or the inner ear, you're actually measuring peripheral temperature. For practical reasons, anytime I talk about measuring body temperature in this particular course, I'll be referring to the peripheral temperature because that's what we can measure rapidly out in the field. I'll also give you a little disclaimer here and let you know that not all medical experts and researchers agree on the exact correlation of core temperature to peripheral temperature. Usually core temperature is one to two degrees higher than the peripheral temperature, but the difference between the two can be greatly reduced when the body is exposed to extreme heat. In extreme conditions, when the body is unable to get rid of heat fast enough, the body's temperature will begin to rise. As your body temperature increases, heat-related illnesses can occur. As body temperatures continue to increase, and they approach 104 degrees Fahrenheit, the body experiences a rapid decline in normal functions, causing cell damage and the eventual shutdown of internal organs, which can be fatal.