Today’s Heat Forecast – Credit NOAA
# 6411
While less dramatic than a hurricane, tornado, or blizzard – heat waves kill more Americans during an average year than all three of those put together. And once again today (and through this weekend) heat indexes will be dangerously high across much of the eastern half of the country.
Counting the number of fatalities due to excessive heat is difficult, since many of those who succumb are elderly, and have other medical conditions.
As Rupa Basu and Jonathan M. Samet wrote in the Journal Epidemiological Reviews (see Relation between Elevated Ambient Temperature and Mortality: A Review of the Epidemiologic Evidence):
An average of 400 deaths annually are counted as directly related to heat in the United States, with the highest death rates occurring in persons aged 65 years or more (3). The actual magnitude of heat-related mortality may be notably greater than what has been reported, since we do not have widely accepted criteria for determining heat-related death (4, 5–7), and heat may not be listed on the death certificate as causing or contributing to death.
This disparity between counted and estimated heat-related deaths can be illustrated by the reports from the infamous heat wave of 1980, which `officially’ claimed `more than 1250 lives’ (cite NOAA Heat Wave: A Major Summer Killer) but which unofficially may have killed as many as 10,000 (Tracking and Evaluating U.S. Billion Dollar Weather Disasters, 1980-2005 (Lott and Ross, 2006).
Eight years later, a heat wave across the central and eastern part of the nation killed as many as 7,500 people (cite). More recently, in 1999, a prolonged heat wave along the Eastern seaboard is believed to have killed 500 (cite).
And in Europe and across Russia a prolonged heat wave in 2010 may have contributed to tens of thousands of deaths (see Recent Heat Waves Likely Warmest Since 1500 in Europe).
Forecasters base their decision to issue heat warnings based on the heat index, a combination of heat and relative humidity, using the chart below:
Excessive heat alert warnings are usually issued when the forecast anticipates a heat index that exceeds 105°-110°F for at least 2 consecutive days. As you can see, when it is extremely humid, actually temperatures don’t have to get much above 90 to become dangerous.
In anticipation of this weekend’s heat wave, the CDC has posted some helpful information on beating the heat on their Have You Heard? website.
Learn more about heat-related illness and how to stay cool and well in hot weather
June 29, 2012
Getting too hot can make you sick. You can become ill from the heat if your body can't compensate for it and properly cool you off. Heat exposure can even kill you: it caused 8,015 deaths in the United States from 1979 to 2003. These are the main things affecting your body's ability to cool itself during extremely hot weather: high humidity and personal factors.
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More Information
For more information, the Excessive Heat Events Guidebook was developed in 2006 by the EPA, the NWS, the CDC, and the DHS to provide the best practices for saving lives during heat waves in urban areas.
Some handy advice for this weekend, or anytime the heat index is excessively high:
Quick Tips for Responding to Excessive Heat Events
For the PublicDo
- Use air conditioners or spend time in air-conditioned locations such as malls and libraries
- Use portable electric fans to exhaust hot air from rooms or draw in cooler air
- Take a cool bath or shower
- Minimize direct exposure to the sun
- Stay hydrated – regularly drink water or other nonalcoholic fluids
- Eat light, cool, easy-to-digest foods such as fruit or salads
- Wear loose fitting, light-colored clothes
- Check on older, sick, or frail people who may need help responding to the heat
- Know the symptoms of excessive heat exposure and the appropriate responses.
Don’t
- Direct the flow of portable electric fans toward yourself when room temperature is hotter than 90°f
- Leave children and pets alone in cars for any amount of time
- Drink alcohol to try to stay cool
- Eat heavy, hot, or hard-to-digest foods
- Wear heavy, dark clothing.
