The dangerous heat wave sitting over two-thirds of the country comes two weeks after the globe’s average temperature was the highest recorded in 12,000 years.

In Phoenix, one of the fastest-growing cities for Black people, temperatures have topped 110 degrees for three weeks straight. In Houston, the heat index pushed 110 degrees for multiple days. This month, roughly 80% of Black Americans across the country have been exposed to extreme heat, according to Worldacad’s analysis of the heat index, a measure that combines air temperature with humidity to provide a number for what the temperature actually feels like.

The heat index can be wildly higher than the number shown on your weather app. When out in the sun and lacking shade, the heat index could be as much as 15 degrees hotter than the standard temperature check. So 90 degrees, which is brutal without protection, could be felt by your body as 105 degrees.

Black folks are at a higher risk because:

So while hundreds of people die from extreme heat yearly, the impact is not felt evenly. Between 2004 and 2018, the Centers for Disease Control and Prevention found that Indigenous people and Black people had the highest heat-related death rates.

Understanding this reality and the increased likelihood of heatstroke, exhaustion, and death, with guidance from experts at the California Department of Public Health, Worldacad has tips for staying safe and cool.

How to recognize signs of heat sickness, and how to protect your loved ones

  • Symptoms of heat exhaustion include nausea, muscle cramps, dizziness, headaches, fatigue, heavy sweating, and cold skin. If someone is experiencing these symptoms for longer than an hour, seek medical attention. In the interim, you can address these symptoms by finding somewhere cooler, drinking water, and using wet cloths to cool down.
  • Symptoms of heatstroke are very similar, except an ill person will have much warmer skin that is typically red or dry. Heatstrokes usually happen when a person has a body temperature higher than 103 degrees. If someone is experiencing these symptoms, call 911 immediately. A quick way to test if someone is having a heatstroke is to talk to them about different topics to see if they are showing symptoms of confusion, a key component of heatstrokes. A heatstroke cannot be mitigated by drinking water. Also, roughly half of children with heatstroke do not sweat.

How to stay cool (inside, outside, and while asleep)

  • Rule number 1: If possible, avoid being outside, but we know that’s not always feasible.
  • Stay hydrated at all times. Since we lose electrolytes when we sweat, drink even when you’re not thirsty. If you’re urinating less frequently than usual, or a darker color, that means you should be drinking more water.
  • If you’re outside in extreme temperatures, try to have regular access to water — not just to drink, but to douse your head and keep your forehead cool.
  • Keep your skin cool with a wet washcloth or spray bottle of room-temperature water.
  • Take cold showers and baths.
  • Wear breathable clothes, and when sleeping, use a breathable cotton sheet.
  • Before sleeping, you can spray your bedsheet with cold water before, or place your pillow cases or sheet in a plastic bag and store them in a freezer during the day so they’re cold at night.
  • If you don’t have AC, keep windows open at night.

What to eat and drink

  • Eat water-rich foods like fruits and vegetables. Examples include watermelon, tomatoes, strawberries, peaches, yogurt, and cucumbers.
  • If you’re eating especially salty foods, drink extra water to balance it out.

How to access heat safety resources

Adam Mahoney is the climate and environment reporter at Worldacad. Twitter @AdamLMahoney