Heat warnings: do people listen?

While much research has focused upon the evaluation of the heat – health relationship and its incorporation into newer heat warning systems, no published study has examined the efficacy of the warning messages broadcast by local authorities. Do heat warnings significantly change the behavior of the general public? To help evaluate this question, an initial survey of the perception and response of elderly residents (those 65 and older) to heat warnings was undertaken. The surveys were conducted in Phoenix, Arizona; Philadelphia, Pennsylvania; Toronto, Ontario; and Dayton, Ohio over the summers of 2004 and 2005. The elderly were chosen as their mortality rates during heat events far outpace the general population. A total of one thousand respondents across these cities were queried within three days of a heat event about their perception of their own vulnerability, changes in daily activities, and knowledge of their municipality's recommendations for how to deal with the oppressive weather. Results suggest that while the public is generally aware of the occurrence of heat warnings, only around half of all respondents actually changed their behavior. Specific activities that the respondents recalled were recommended varied from city to city, but the primary actual response was to avoid the outdoors at all costs. Moreover, while all respondents were at least 65 years of age, many did not feel that the recommendations for the elderly included them. Though most residents owned or had access to air conditioning, in the northern cities a smaller percentage actually utilized an air conditioner during the heat event.