This document, Heat Wave A Summer Killer, is a short National Weather Service Document informing us about the heat index and the dangers of excessive heat.
Heat kills by taxing the human body beyond its abilities. In a normal year, about 175 Americans
succumb to the demands of summer heat. Among the large continental family of natural hazards,
only the cold of winter-not lightning, hurricanes, tornadoes, floods, or earthquakes-takes a greater
toll. In the 40-year period from 1936 through 1975, nearly 20,000 people were killed in the United
States by the effects of heat and solar radiation. In the disastrous heat wave of 1980, more than
1,250 people died. And these are the direct casualties. No one can know how many more deaths are advanced by heat wave weather-how many diseased or aging hearts surrender that under better conditions would have continued functioning.
North American summers are hot; most summers see heat waves in one section or another of the
United States. East of the Rockies, they tend to combine both high temperature and high humidity
although some of the worst have been catastrophically dry.
The NWS will initiate alert procedures when the HI is expected to exceed 105°- 110°F (depending on local climate) for at least two consecutive days. The procedures are:
- Include HI values in zone and city forecasts.
- Issue Special Weather Statements and/or Public
Information Statements presenting a detailed
discussion of (1) the extent of the hazard
including HI values, (2) who is most at risk,
(3) safety rules for reducing the risk.
- Assist state/local health officials in preparing Civil
Emergency Messages in severe heat waves.
Meteorological information from Special Weather
Statements will be included as well as more
detailed medical information, advice, and names
and telephone numbers of health officials