Science, 29 July 2024
Studies in climate chambers show humidity adds danger, but analyses of population-wide mortality rates suggest otherwise
Does humidity make heat more deadly? Scientists are divided
Last summer, while the Northern Hemisphere endured record-breaking heat, a paper in Environmental Health Perspectives (EHP) generated a stir among scientists who study heat’s risks to health. The paper pointed out a startling disconnect between two camps of researchers on whether humidity makes hot weather more deadly.
Physiologists have found strong evidence that humidity matters: at a given temperature, more humidity makes it harder for the body to maintain a safe core temperature and ward off heat stroke. Epidemiologists, by contrast, have concluded that temperature alone accurately predicts heat-related death rates; adding humidity does little to improve their predictions.