USA – A record-breaking heatwave in the USA have left 160 million people under heat alerts as temperatures soar past 43C.

The National Weather Service said that extreme heat warnings had been issued for 75 million residents in major cities, including New York, Boston, Chicago, Philadelphia and Washington, D.C. Temperatures in Mitchell, South Dakota, reached 104 degrees Fahrenheit (40 degrees Celsius), surpassing the previous record of 101°F (38.3C).

Heat index values, the combination of heat and humidity, exceeded 110°F (43.3C) in parts of North Carolina and Virginia by midday Monday.

Several areas across the Northeast are expected to feel similar conditions through Tuesday, with Boston’s forecast predicting “dangerous levels of heat, with no significant relief at night.”

“This is a dangerous level of heat,” the Boston office of the National Weather Service said on X. “Tuesday will be the hottest day of the stretch.”

New York City Mayor Eric Adams urged residents to remain cautious.

“SEVERAL DAYS of EXTREME heat,” Adams warned.

Relief is expected on Wednesday in the Midwest and Thursday in the Northeast, when the system weakens. Severe storms, however, are forecast across Kansas, Michigan, Texas and Wisconsin, bringing flooding, hail and possible tornadoes.

While attributing individual heat waves to climate change remains complex, scientists have linked rising global temperatures to more frequent and prolonged heat events.