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, and climate projections indicate that extreme heat events will be more frequent and intense in coming decades.
Some heat-related illness and death risks have diminished in recent decades, possibly due to better forecasting, heat-health early warning systems, and/or increased access to air conditioning for the U.S. population. However, extreme heat events remain a cause of preventable death nationwide. Urban heat islands, combined with an aging population and increased urbanization, are projected to increase the vulnerability of urban populations to heat-related health impacts in the future.
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. While deaths and injuries related to extreme cold events are projected to decline due to climate change, these reductions are not expected to compensate for the increase in heat-related deaths.
Watch a short video about climate-related health effects from extreme heat, and what communities can do to prepare.
CDC Temperature Extremes 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 StoryMapexternal icon – learn how the CRSCI Grant Recipients are preparing for and responding to increasing temperatures
- Extreme Heat Can Impact Our Health in Many Ways pdf icon[PDF – 107 KB]
- Heat Exposure and Cardiovascular Health: A Summary for Health Departmentspdf icon[PDF – 7 MB]
- Heat & Health Tracker – Explore how extreme heat affects your county, populations that are at risk, and resources for response.
- Heat Vulnerability and Projection Data – Tracking Portal – interactive maps, tables, and charts
- Social Media on Extreme Heat