(NewsNation) — Heat waves, like the ones being seen by over 100 million people across the country this week, are the leading cause of weather-related deaths. High temperatures, on average, cause more fatalities than other kinds of dangerous weather.

More than 600 people in the United States are killed by extreme heat every year, according to the Centers for Disease Control and Prevention. In comparision, the National Weather Service reports that about 80 tornado deaths a year are reported. In 2021, 145 people were killed in floods.

Heat-related conditions, per the CDC, include hyperthermia, where exposure to extreme heat causes the body to become unable to property cool; heat exhaustion; and heat stroke. Symptoms of heat exhaustion include

  • Muscle cramping
  • Fatigue
  • Headache
  • Nausea or vomiting
  • Dizziness or Fainting

People at greatest risk of a heat-related illness include infants and children up to 4 years old, people older than 65, those living in poverty, people who are socially isolated and people with existing medical conditions, such as diabetes or heart disease.

To beat the heat, experts say to drink plenty of water and avoid being out in the sun. The CDC says to wear sunscreen, choose lightweight, light-colored, loose-fitting clothing and stay in an air-conditioned place as much as possible. Those who live in homes without air conditioning might even be eligible for assistance.