Question of the Week

July 25, 2005


It has been hot outside!

In Phoenix, Arizona, where many expect it to be hot, weather has been dangerously above normal for those who have to leave the air conditioned buildings, or for those who do not have access to air conditioning at all.

"Friday, July 22, 2005
PHOENIX -- A record heat wave has led to the deaths of 18 people, most of them homeless, leaving officials scrambling to provide water and shelter to the city's transient population. For the first time in years, homeless shelters opened their doors during the day to offer respite from the blistering sun, which has delivered above-average temperatures every day since June 29 [average highs for this time of year are 104*F - 105*F according to statistics found on]. Police began passing out thousands of water bottles donated by grocery stores, and city officials set up tents for shade downtown. ... 'Most of us just run from air-conditioned box to air-conditioned box, so it's hard to imagine how omnipresent the heat really is for the homeless here,' said Phoenix police Sgt. Randy Force. ... By Wednesday, the high still climbed to 109 degrees. Even during the coolest part of the day, the mercury has failed to descend lower than 89 degrees."

This heat brings to mind the homeless living outdoors day and night. Also affected are those with jobs that require them to be working outside (construction workers, mail carriers,...). And it is not just Arizona, or even just the Southwest, that is feeling the heat. Cities that are not used to such high temperatures are trying to help the many in their communities that do not have air conditioning in their homes.

"Jul 25, 2005 9:28 am US/Central Heat Wave Brings Triple-Digit Temps To Midwest... More than 200 cities and towns in the western part of the United States have set heat records this summer. Chicago, Ill. and St. Louis, Mo. hit 102 degrees on Sunday, while Iowa City, Iowa and Phoenix, Ariz. hit 101. In Iowa, the heat index made it feel like 113 degrees outside this weekend. Chicago's heat index topped 105, a big concern in a city where many residents don't have air conditioning. Both Des Moines, Iowa and Chicago opened cooling centers to help people escape the heat. In Illinois, emergency workers went door-to-door checking on senior citizens. They urged everyone to check on their neighbors."

As the heat left the Midwest, it headed east.

"July 25, 2005 - It will be dangerously hot across most of South Carolina Monday afternoon. ... The weather service says heat index levels could reach 110 in the Upstate between noon and 6:00pm. City officials are urging citizens to use caution this week."

While people may think to "use caution" in a tornado or hurricane, the dangers of heat are sometimes forgotten.

"Heat is the number-one weather killer in this country. Extreme heat and humidity associated with heat waves directly killed on average at least 237 people a year in the United States for the period of 1994-2003."

How does heat become dangerous?

"Our bodies dissipate heat by varying the rate and depth of blood circulation, by losing water through the skin and sweat glands, and as a last resort, by panting, when blood is heated above 98.6°F. Sweating cools the body through evaporation. However, high relative humidity retards evaporation, robbing the body of its ability to cool itself. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat related illnesses and disorders may develop."

"Heat related illnesses and disorders" include:

"Heat Cramps: Muscular pains and spasms due to heavy exertion. Although heat cramps are the least severe, they are often the first signal that the body is having trouble with the heat.

"Heat Exhaustion: Typically occurs when people exercise heavily or work in a hot, humid place where body fluids are lost through heavy sweating. Blood flow to the skin increases, causing blood flow to decrease to the vital organs. This results in a form of mild shock. If not treated, the victim's condition will worsen. Body temperature will keep rising and the victim may suffer heat stroke.

"Heat Stroke: A life-threatening condition. The victim's temperature control system, which produces sweating to cool the body, stops working. The body temperature can rise so high that brain damage and death may result if the body is not cooled quickly."

Just plain high temperatures can be dangerous. Add to that a Heat Wave, or a high Heat Index, and conditions can get even more hazardous.

"Heat Wave: Prolonged period of excessive heat, often combined with excessive humidity.
"Heat Index: A number in degrees Fahrenheit (F) that tells how hot it feels when relative humidity is added to the air temperature. Exposure to full sunshine can increase the heat index by 15 degrees."

With the heat that has hit this July (2005), Heat Index has been mentioned frequently.

"The Heat Index (HI) is the temperature the body feels when heat and humidity are combined. The chart below shows the HI that corresponds to the actual air temperature and relative humidity. (This chart is based upon shady, light wind conditions. Exposure to direct sunlight can increase the HI by up to 15*F.)"
(Charts are available at the above site)

If the Heat Index is higher, it is even harder for the body to cool itself. This is not just a number that means it feels hotter; this is a number that means your body is heating up -- and struggling to cool -- as if it were this other temperature. (Just as higher humidity can raise the heat index tens of degrees, very low humidity can drop the heat index a couple of degrees and help the body cool itself as if it were the lower temperature.)

Questions of the Week:
What does all this mean to you? What can you and your friends do to stay healthy, safe, and cool when temperatures begin to rise where you live? If you live in an area where high temperatures are not as common (and so air conditioning is not as common), what can you do to stay cooler, and to keep your home cooler, during the extreme heat outdoors. What weather terminology should you know to help you understand the heat being reported? What members of your family and members of the community (including members of the work force) are most susceptible to the heat? How can you help those in your family and community stay safe and healthy when temperatures get high?

Please email me with any ideas or suggestions.
Note: Due to increasing amounts of SPAM sent to this account, please include "QOW" in the subject line when sending me email.

I look forward to reading what you have to say.

Health Community Coordinator
Access Excellence @ the National Health Museum

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