Assessing the Relationship between Wet Bulb Globe Temperature and Heat-Related Illness Incidence in the Greater Houston Area

Heat-related illnesses are the largest contributor to weather-related fatalities across the US, resulting in an average of over 700 deaths and 60,000 emergency room visits each year. The impacts of excessive heat events are felt more strongly in large urbanized areas like greater Houston, where the impacts of the urban heat island effect further exacerbate the problem. With the risk of heat-related illnesses continuing to increase due to the combined impacts of continued urbanization and climate change, the issue of excessive heat will become increasingly critical across the weather and climate enterprise. Because of this, metrics like the Wet Bulb Globe Temperature (WBGT) have attracted recent interest as they may offer a more robust measure of heat stress than the currently used NWS Heat Index.

Building upon previous work which created the first gridded climatology of WBGT across the United States, we identify a relationship between heat-related illness incidence and WBGT across the Greater Houston Area using a multi-year Emergency Medical Services (EMS) call dataset provided by several National Weather Service core partners. In performing this analysis, we discuss the spatial and temporal trends in EMS heat-related call volume with varying WBGT magnitude across a diverse urban area. In doing so, we seek to leverage the combined power of these two datasets to determine critical thresholds of WBGT that result in increased health impacts in order to better provide helpful decision support services to core partners during periods of excessive heat.