Laserfiche WebLink
0 <br />Human bodies dissipate heat in one of three ways: by <br />varying the rate and depth of blood circulation; by <br />losing water through the skin and sweat glands; and <br />by panting. As the blood is heated to above 98.6°F, <br />the heart begins to pump more blood, blood vessels <br />dilate to accommodate the increased flow, and the <br />bundles of tiny capillaries penetrating through the <br />upper layers of skin are put into operation. The <br />body's blood is circulated closer to the surface, and <br />excess heat is released into the cooler atmosphere. <br />At the same time, water diffuses through the skin as <br />perspiration. The skin handles about 90% of the <br />body's heat dissipating function (Darling). <br />Heat disorders generally have to do with a reduction <br />or collapse of the body's ability to cool itself by <br />circulatory changes and sweating, or a chemical (salt) <br />imbalance caused by too much sweating. When the <br />body cannot cool itself, or when it cannot <br />compensate for fluids and salt lost through <br />perspiration, the temperature of the body's inner core <br />begins to rise and heat -related illness may develop. <br />Studies indicate that, other things being equal, the <br />severity of heat disorders tends to increase with age. <br />Heat cramps in a 17 -year-old may be heat exh iustion <br />in someone 40, and heat stroke in a person over 60 <br />Darling). <br />When the temperature gets extremely high, the <br />National Weather Service has increased its efforts to <br />alert the general public as well as the appropriate <br />authorities by issuing Special Weather Statements. <br />Residents should heed these warnings to prevent <br />heat related medical complications. As a result of <br />the latest research findings, the National Weather <br />Service has devised the "Heat Index" (HI). The HI, <br />given in degrees Fahrenheit, is an accurate measure <br />of how hot it really feels when relative humidity is <br />added to the actual air temperature. The National <br />Weather Service will initiate alert procedures when <br />the HI is expected to exceed 105°F for a least two <br />consecutive days. Possible heat disorders related to <br />the corresponding HI are listed below (Darling). <br />Indian River County Comprehensive Emergency Management Plan Basic Page 16