Our bodies react differently to extreme heat depending on how much humidity is in the air. Heat index is a measure of how hot it feels outside, taking into account both air temperature and relative humidity. As the humidity rises, the heat index rises. In dry heat, our sweat quickly evaporates, which helps lower our internal temperature; but on a humid day, our sweat cannot fully evaporate as the air is already damp, and this prevents us from effectively cooling off. It also raises our risk of heat stroke and even death. To illustrate the science, this podcast considers the case of a man who was lost for three weeks in a remote desert in southern Utah and survived. Listen to hear more about dry versus wet heat and how it affects the human body.
Story Length: 6:17
AIR DATE: 02/01/2016