The number of heat waves that place the nation's elderly at risk for death has been increasing steadily since 1949 and shows no signs of abating, the National Oceanic and Atmospheric Administration reported December 9, 1998. The rise in heat waves is consistent with what others have predicted would happen with global warming. The highest heat indexes were in the East and Midwest.
Humidity magnifies the health risk of high temperatures.
Co-author Rebecca Ross says the increase in heat waves is the result of a rise in average temperatures for the same period. Higher humidity levels may reflect urbanization and more water vapor from ocean evaporation. Gaffen also has preliminary data, which have not been reported, that suggest the number of extremely cold days during winter is falling. The Centers for Disease Control and Prevention documents a clear increase in deaths during heat waves. Michael Gage, deputy director of the CDC division of environmental hazards and health effects, says that if heat waves continue, cities will need to provide the elderly more shelters and access to air conditioning.