Caution urged as heat dome moves over Midwest, much of U.S.

With the entire Midwest and most of the east half of the country expecting temperatures in the 90s to the low 100-degree range, officials are warning that precautions should be taken to stay safe.
Heat is no small matter, as an analysis of heat-related deaths in the U.S. from the last 25 years, published in JAMA, the Journal of the American Medical Association, points out. The number of people who died in those years has generally increased, “especially during the last seven years.”
Last year, the study said that 2,325 people died of heat-related causes, noting that could be an underestimation.
The Chicago area is expected to be swelter central, but the high temperatures radiate out through the South and then up the Eastern seaboard. And Southern California, as well as parts of Arizona and New Mexico, look to have a few very high-temperature areas in coming days. While most are in the 90s, there are a few 100- to 108-degree days coming. Phoenix is predicted to hit 110 degrees by Tuesday. And other factors can make it feel hotter.
The National Weather Service predicts “extreme” heat risk in Chicago; Des Moines, Iowa; and the Twin Cities area. Meanwhile, a dozen states are going to see “major” heat, where heat and humidity combine for temperatures of 105 degrees to 115 degrees.
“Forecast highs in the mid-90s to near 100 combined with high humidity will send heat indices into the 105–115-degree range, with widespread heat-related advisories and warnings in place,” the National Weather Service reported in an urgent weather message. In a post on X, the Weather Prediction Center noted that “records may be broken.”
By Saturday, the risk will be low to moderate for most parts of the country, according to a National Weather Service map.
But even moderately high temperatures can pose risk if people overexert outdoors or become dehydrated. And for those who don’t have adequate air conditioning or somewhere to go that is cooler, it can be, at best, very uncomfortable.
In the heat deaths study, the researchers, led by the University of Texas at San Antonio, suggest that “local authorities in high-risk areas should consider investing in the expansion of access to hydration centers and public cooling centers or other buildings with air conditioning.”
But people need to take their own precautions, as well, starting with drinking plenty of fluids even when you don’t feel really thirsty. Older people and young kids, especially, may not get thirst promptings to tell them to hydrate.
In its weather report, WNDU-TV in South Bend, Indiana, said to make sure that “pets are off the pavement by late morning into the early evening hours. This is also a reminder to NEVER leave the pets and children alone in a vehicle,” the station said.
The National Weather Service separately pointed out that heat is especially dangerous when it “lingers more than one day.” And bodies have to have some cool-down time, so hot days and nights that don’t cool enough are bad combinations.
“Heat islands” are also a problem. Many cities have so-called “heat islands,” made up of lots of concrete and impermeable services. They collect heat during the day and radiate it out at night, keeping temperatures hot. One aid for that is plenty of trees that provide shade and cool things down, as Deseret News has reported. Shade from a tree can shave as much as 20 degrees from the temperature. But trees are also at risk in heat islands. They can be stressed by heat.
If you have air conditioning on a hot day, the problems are minimal. But those who don’t may need to find somewhere cooler to be.
Besides staying inside when it’s too hot and drinking lots of fluid, as well as avoiding too much exertion, you can also help those around you by checking on them when temperatures are very high.