According to last year’s National Climate Assessment, the number of hot days in the United States is increasing while the frequency of heat waves is has also increased. Now, much of continental United States is under threat of potentially deadly heat waves from record-breaking temperatures.

Record-Breaking Temperatures

The National Weather Service is warning of a dangerous heat wave building in the central and eastern United States. Over 150 million Americans are affected by the heat advisory, with the Thursday advisory expected to affect Mississippi and the Midwest and moving on to the Northeast by Friday and Saturday.

Chicago, Oklahoma, St. Louis, Memphis, and Detroit are just some of the cities included in the Thursday heat advisory, while Cleveland, Washington, Baltimore, Pittsburgh, Boston, and New York are all expected to experience high temperatures this weekend and are therefore under excessive heat watch. In many highly populated areas, the heat index is expected to peak at 110 degrees Fahrenheit (43.3 degrees Celsius) between Friday and Sunday.

“Dozens of record high minimum temperatures are forecast to be set across the eastern U.S., and a handful of record high maximum temperatures will be challenged,” the advisory states.

Potentially Deadly Heat Wave

With the heat advisory, people are advised to look out for signs of heatstroke and heat exhaustion. In fact, in Maryland, two people have already reportedly died from heat-related causes.

Signs of a heat exhaustion may include sweating, dizziness, and fainting, while a heatstroke warning signs include sweating, spasms, and pain. These are real medical emergencies that require immediate attention, and anyone who observes someone experiencing these symptoms must immediately call 911 and try to lower the body temperature of the patient by putting cool sponges or blankets on them or placing them in a cool bath. What’s important is to try and lower the patient’s body temperature to 101 or 102 Fahrenheit (38.3 or 38.8 degrees Celsius).

These are important things to take note of as the extreme temperatures are expected to persist even in the evening, so even homes would not have the opportunity to cool off at night.