The State of Iowa’s Heat Awareness Day for 2012 is June14.
June 9, 2011
One of the most deadly weather phenomena to hit our region each summer is heat. Many people do not realize how deadly heat can be. In contrast to the visible, destructive, and violent nature of thunderstorms, tornadoes, and floods, heat is a silent killer. Heat kills by taxing the human body beyond its abilities.
In a normal year, about 175 Americans succumb to the demands of summer heat. In fact, in a 40-year period from 1936-1975 nearly 20,000 people were killed in the United States by the effects of heat and solar radiation. In a 1995 heat wave, more than 700 deaths in Chicago, IL were attributed to the heat. And these are the direct casualties. No one can know how many more deaths are advanced by heat-wave weather.
Cities pose special hazards when it comes to heat. The stagnant atmosphere traps pollutants in urban areas, which adds to the stresses of hot weather. In addition, concrete, asphalt and other industrial materials common in cities trap heat during the day, and keep the air temperature warmer at night.
Heat Advisory:
Heat Index values are expected to reach or exceed 105 degrees or an absolute maximum temperature of 100 degrees is expected in the next 24 hours.
Excessive Heat Watch:
Conditions are favorable for temperatures to reach
excessive heat criteria in the next 12 to 48 hours.
Excessive Heat Warning:
Heat Index values are expected to reach or exceed 110 degrees, and not fall below 75 degrees, for at least a 48 hour period beginning in the next 24 hours.
WHAT TO LISTEN IFOR:
The Heat Index (HI) is also sometimes referred to as the “apparent temperature” and is a measure of how hot it feels outside. The HI includes the influence of relative humidity and, in general, as the relative humidity increases, the apparent temperature also in-creases. To figure out the HI you can look at the Heat Index Chart (top right) and find the intersection of the air temperature and relative humidity. The shaded zones on the chart correspond to increased probabilities of developing heat related disorders. It is important to note that the HI values were devised for shady, light wind conditions, and therefore, exposure to full sunshine can increase HI values up to 15°F.
For more information on any emergency preparedness topic contact the Tama County Emergency Management Agency at: (641) 484-6261, http://www.tamacounty.org/ or rcurrens@ema.tamacounty.org