It’s been a hot week for millions of people across the US, and it’s not over yet. A heat wave has shattered daily temperature records across the Southwest, Central Plains, and Midwest this week. More than 100 million people in the US have been under some type of heat alert and advised to stay indoors.

Two people died in the Milwaukee area amid the extreme temperatures — a 39-year-old woman found in her home and an 89-year-old man who collapsed in his yard. The medical examiner’s office said they were “probable” heat deaths, according to NBC News. Another man, 67, was found dead in California’s Death Valley National Park, after he ran out of gas and walked through the heat.

Tens of thousands of people faced power outages. School districts in Michigan cancelled classes, and public schools in Pittsburgh, Pennsylvania, switched to half days to avoid the hottest hours, ABC News reported. In Odessa, Texas, a main water line broke, leaving residents to weather the heat without running water for more than 48 hours, The Texas Tribune reported.


In Kansas, an estimated 2,000 cattle died from heat stress as of Tuesday, according to Reuters. “It’s really a combination of the heat and the humidity which causes some of these impacts,” Marc Chenard, a meteorologist with the National Weather Service, told Insider. “It really depends on how used to that type of weather these areas are, and also the time of year. So for some parts of the country, it might be a little bit early for some of this heat and humidity.”

Humidity can make extreme temperatures feel even hotter, since it hinders the cooling process of sweat evaporating off people’s skin. That’s why humidity can push the heat index 10-15 degrees higher than the actual temperature.

Milwaukee’s heat index hit a record June high of 109 degrees Fahrenheit on Tuesday. Las Vegas, too, reported 109 degrees. North Platte, Nebraska, snagged its own June record of 108 degrees. Phoenix, Arizona, rose even further to 114 degrees. Death Valley topped them all at 123 degrees.

The heatwave means higher demand for energy across the metro and across the Midwest, which could put a strain on equipment used in the power grid. The hot weather likely contributed to a transformer failure that knocked out power to more than 10,000 people Monday.

At about 3:45 p.m. Monday, an Evergy transformer failed and left some without power in the hottest part of the day. “Typically, when we see high heat and high demand, it’s possible we could see an equipment failure like we did. That’s also to say that when we see milder temperatures, that’s also possible too,” said Andrew Baker, of Evergy.

Everybody’s power was restored about 10 p.m. Monday. Evergy stressed this was an equipment failure and not any kind of a blackout due to a strain on the power grid. “Emergency interruption, commonly referred to as rolling blackouts, are not anticipated at this time. Currently, we have the adequate supply needed to meet customer demand through the summer,” Baker said.