Heat Waves may Affect Your Health

High summer temperatures can burden elderly adults with chronic disease

(RxWiki News) People who live in warm climates may be more used to the scorching heat of summer. These folks are better equipped to handle high temperatures.  However, for people from colder regions, heat may become a major health shock.

Researchers have been watching the heat index since 1985 in comparison to high-risk elderly adults and discovering that the sharp increases in high heat over the summers is having a tough impact on these people with increased mortality rates.

Statistically, researchers found that zip codes with larger proportions of green-covered areas had lower mortality rates for the risk group.

"Discuss with your doctor a plan for dealing with a sudden heat-wave."

Lead author, Antonella Zanobetti, Ph.D., Harvard School of Public Health, and her team looked at adults over the age of 65 in 135 U.S. cities with chronic diseases in relation to the temperature. They looked at 3,749,096 people with chronic obstructive pulmonary disease (COPD), 3,364,868 with diabetes, 1,939,149 with congestive heart failure, and 1,454,928 who had experienced at least one heart attack to see if climate change and rising summer temperatures increased mortality rates.

As little as 1 degree Celsius increase in the variability of summer temperature could cause a 2.8% to 4% rise in the death rate for elderly with one of these chronic conditions. Researchers took into account other factors like smoking history, ozone levels and winter temperatures that might influence the statistics outside of hot weather. It appears that the larger the swings for summer temperatures, the higher the death rate.

Those with congestive heart failure or diabetes tended to be more likely to die from the heat than those with COPD or people having experienced only one heart attack with 1.2% to 2% higher mortality rates.

Cities with a good amount of grass-covered land had lower mortality rates among their elderly by 1% to 2%.

People can adapt to certain temperatures, but sudden or unusually extreme heat or cold doesn’t allow time for bodies to adjust. The stress of the chronic disease makes it more difficult for the body to regulate its temperature and acclimate to the heat.

If people are used living in the heat, then they are going to be less drastically affected by yet another summer. Whereas, heat waves in northern regions are a little more shocking to the system.

Senior researcher for the study, Joel Schwartz Ph.D., professor of environmental epidemiology at Harvard School of Public Health, says, "People adapt to the usual temperature in their city. That is why we don't expect higher mortality rates in Miami than in Minneapolis, despite the higher temperatures...But people do not adapt as well to increased fluctuations around the usual temperature."

It's important for people with serious health problems to be aware of temperature changes and try and prepare for heat waves as best as they can.

This study will be published in the Proceedings of the National Academy of Sciences USA, April 2012. No conflicts of interest were found. The research was funded by the grants from the U.S. Environmental Protection Agency and the National Institute of Environmental Health Sciences.

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Review Date: 
April 7, 2012