Risk Factors in Heatstroke-Reply

Abstract

In Reply.— We appreciate the thoughtful comments of Drs Parrotte and Caldroney on our exploratory case-control study of risk factors for heatstroke. We noted relatively few nonfatal cases of heatstroke among occupants of homes well shaded by trees, suggesting that such shading prevents heatstroke. Fully shaded windows reduce solar heat gain as much as 80%, 1 and the role of trees and foliage in providing shading has been recognized. 2,3 We have been wary of overinterpreting our findings. However, a causal relationship between shading and decreased heatstroke incidence seems plausible. In undertaking our study, we were aware of previous work (including that of Shapiro et al) that suggested that survivors of past heatstrokes are more vulnerable to thermal stress than persons never before affected. Therefore, we specifically sought a history of prior heatstroke in all 156 cases and in the 462 control subjects studied. (Demographic characteristics, including age, of the