A Washington State resident arranges cardboard above an air conditioning unit during soaring temperatures on July 28, 2022.

Extreme high temperatures are set to become more regular in the US by the middle of the century after several waves of dangerous heat this year. A heat belt stretching from Texas up to Wisconsin will expose people to stretches of heat index above 100 degrees Fahrenheit (37 degrees Celsius), as well as less frequent but still terrifying days above 125 degrees Fahrenheit (52 degrees Celsius), according to researchers.

A huge column of the country could see a big increase in extreme heat by the year 2053. The middle of the country will have a heat index of more than 125 degrees.

About 8 million Americans have been affected by the high heat index this year, but the number will rise to over 100 million by the middle of the century according to the model. Several major cities would be covered by the future heat belt.

The red areas represent places that will have at least one day a year of extremely dangerous heat index above 125 degrees Fahrenheit (52 degrees Celsius). Top shows the projection for 2023; bottom shows 2053.

First Street has an extreme heat model that looks at factors like tree cover and proximity to water. Data about current high temperatures are factored in by the model. In a middle-of- the-road future emissions scenario, greenhouse gas emissions peak in 2040 and begin to decline. The harder it is to stay cool the more humid it is. It will be hard for people to be outside due to the rising temperatures and humidity. The risk factor tool was updated by the First Street Foundation. To see if their community will see a rise in heat, flood, and fire risks in the next 30 years, users can plug in their address.

The length of consecutive days of heat index above 100 degrees Fahrenheit (38 degrees Celsius) will increase in a few decades.

The American Midwest will be badly affected by heat because it is not large enough to absorb the heat. It doesn't mean that the states along the coasts and the Gulf will be spared; areas across the coastal Mid-Atlantic and Southeast will experience higher heat index.

The report states that heat waves will change over time. The Gulf of Mexico and the southeastern Atlantic Coast have a heat index over 100 degrees Fahrenheit. The model projects will take an average of 120 days to complete. The states of Texas, Arizona, and Florida will see more days of consecutive heat. It means little respite for people in heat islands across the U.S., and even less for people with little access to resources to stay cool.

More days of extreme heat are expected as Earth warms; if we fail to limit warming to under 2 degrees Celsius, heat will be one of the many ways that humans will suffer terribly due to an altered global climate.