What to know
Extreme heat events are becoming more frequent and intense. Deaths result from heat stroke and related conditions, but also from cardiovascular disease, respiratory disease, and cerebrovascular disease.
Heat events in the U.S.
Extreme heat events have long threatened public health in the United States. Many cities, including St. Louis, Philadelphia, Chicago, and Cincinnati, have suffered dramatic increases in death rates during heat waves. Deaths result from heat stroke and related conditions, but also from cardiovascular disease, respiratory disease, and cerebrovascular disease.
Heat waves are also associated with increased hospital admissions for cardiovascular, kidney, and respiratory disorders. Extreme summer heat is increasing in the United States. Climate projections indicate that extreme heat events will be more frequent and intense in coming decades.
Heat-related illness
Improved forecasting, early warnings, and increased air conditioning access may contribute to recent reductions in heat-related illness and death risks. However, extreme heat events remain a cause of preventable death nationwide. Urban heat islands, along with aging and urbanization, will likely heighten urban populations' vulnerability to future heat-related health impacts.
Milder winters resulting from a warming climate can reduce illness, injuries, and deaths associated with cold and snow. Vulnerability to winter weather depends on many non-climate factors, including housing, age, and baseline health. Climate change may reduce deaths and injuries from extreme cold, but it won't offset the rise in heat-related deaths.
Watch a short video about climate-related health effects from extreme heat, and what communities can do to prepare.
CDC resources
- Extreme Cold – Prepare for winter storms, prevent cold temperature-related health problems, and protect yourself during all stages of a winter storm.
- Extreme Heat – helpful tips, information, and resources to help you stay safe in the extreme heat this summer
- Extreme Heat Adaptation StoryMap – learn how the CRSCI Grant Recipients are preparing for and responding to increasing temperatures
- Extreme Heat Can Impact Our Health in Many Ways
- Heat Exposure and Cardiovascular Health: A Summary for Health Departments
- Heat & Health Tracker – Explore how extreme heat affects your county, populations that are at risk, and resources for response. More information about the Heat & Health Tracker is provided on the Fact Sheet.
- Heat Vulnerability and Projection Data – Data Explorer – interactive maps, tables, and charts
- Social Media on Extreme Heat