Extreme Heat
Environmental Risk Factor
Extreme heat is the deadliest weather-related hazard in the United States, killing more Americans annually than hurricanes, tornadoes, and flooding combined. Climate change is increasing the frequency, intensity, and duration of heat waves across the country. Urban heat islands amplify temperatures in cities, where dark surfaces and lack of tree canopy can make temperatures 10-20°F hotter than surrounding rural areas. Extreme heat disproportionately affects outdoor workers, elderly residents, those without air conditioning, and people experiencing homelessness. As global temperatures continue to rise, heat risk is expanding into regions historically unprepared for extreme temperatures.
How It's Measured
Extreme heat risk is measured using historical temperature data, urban heat island mapping, projected temperature increases, and vulnerability assessments. Key metrics include the number of days above 100°F, nighttime minimum temperatures (which affect the body's ability to recover), heat index values combining temperature and humidity, and the rate of temperature increase. We also consider the proportion of households without air conditioning, tree canopy coverage, and local emergency heat response plans.
Health Effects
- ⚠️Heat stroke and heat exhaustion, potentially fatal
- ⚠️Cardiovascular stress leading to heart attacks
- ⚠️Kidney disease from chronic dehydration
- ⚠️Worsened respiratory conditions from heat-related air quality decline
- ⚠️Increased premature births and pregnancy complications
- ⚠️Mental health impacts including increased aggression and suicide
Data Sources
- 📊NOAA Climate Data Online temperature records
- 📊CDC Heat and Health Tracker
- 📊NASA/USGS Landsat urban heat island mapping
- 📊First Street Foundation heat risk model
How to Protect Yourself
- ✓Stay hydrated and avoid outdoor activity during peak heat hours
- ✓Know the locations of cooling centers in your community
- ✓Check on elderly and vulnerable neighbors during heat waves
- ✓Use light-colored curtains or reflective window film to reduce indoor heat
- ✓Plant shade trees around your home to reduce heat exposure
- ✓Ensure your air conditioning is maintained and functioning before summer