Accumulating evidence indicates that environmental temperature substantially affects economic outcomes and violence, but the reasons for this linkage are only partially understood. While factors external to human beings (such as agricultural production) are known to respond adversely to high temperatures, extreme temperatures could also directly influence the internal mental processes governing decision-making. We study this by systematically evaluating the effect of thermal stress on multiple dimensions of economic decision-making, judgment, and destructive behavior with 2,000 participants in Kenya and the US who were randomly assigned to different
temperatures in a laboratory. We find that heat significantly affects individuals’ willingness to voluntarily destroy other participants’ assets, with pronounced increases among those experiencing heightened political conflict in Kenya. We find that other major dimensions of economic decision making are largely unaffected by temperature.