(RxWiki News) When heat waves occur in early summer as opposed to late summer, people are more likely to die, according to a new Yale University study.
The risk of mortality increases 5.04 percent during the first heat wave of summer, compared to 2.65 percent for heat waves that occur later in the season. That may be because individuals are less accustomed to the heat early in the summer and may not protect themselves properly, said Michelle Bell, a co-author of the study and associate professor of environmental health at the Yale School of Forestry & Environmental Studies.
The study determined that the average daily risk of non-accidental death increased on average by 3.74 percent during summer heat waves that occurred from 1987 to 2005 in 43 U.S. cities. The mortality rate increased by 2.49 percent for each 1-degree Fahrenheit increase in mean temperature and 0.38 percent every day a heat wave continued.
Mortality risk was greater in the Northeast and Midwest than in the South perhaps because air conditioning is more prevalent in the U.S. lower regions, which are more accustomed to heat. Interestingly mortality rates did not increase during heat waves in southern cities such as Dallas, Charlotte and Tulsa.