US midwest braces for hottest days this summer, with 55m under heat alerts

A heatwave has left US midwest states confronting what may be some of the most sweltering days the region has seen this summer, with 55 million people included in alerts over the conditions.

A late-season high-pressure system over cities such as Chicago; Des Moines, Iowa; and Topeka, Kansas, has left them experiencing rare “ extreme heat ” for a long period of time, “with little to no overnight relief”, according to the National Weather Service.

States in the region have set up several public cooling centers in preparation for the dangerous heat.

An air quality alert is in effect in states including Iowa, Illinois, Kentucky, Missouri, Ohio and Tennessee, where heat indices are forecast to reach 105F (40.5C) to 115F (46.1C). Experts recommended residents to limit prolonged outdoor activity, especially those with chronic respiratory illnesses.

Students in the region are scheduled to go back to school this week amid the scorching temperatures. Monday is the first day of school for Chicago public school students, who were expected to attend classes as normal despite the heat warnings. However, officials had planned to either cancel outdoor activities or move them indoors.

In a public statement addressing the heat, school officials said “all … classrooms are equipped with air conditioning, and our facilities team will be working with schools to fix any air-conditioning systems that may encounter issues.

“We will make sure that staff and students remain sufficiently hydrated.”

The district said it would keep shades drawn in classrooms to keep out sunlight – and close doors in rooms cooled with window air-conditioner units.

The climate crisis, caused largely by the burning of fossil fuels, forest destruction and methane emissions, means heatwaves are increasing “in frequency, duration, intensity and magnitude”, according to the World Health Organization .

Related: ‘Check on your neighbors’: how isolation makes extreme heat more deadly

Last week, a heat dome covered large swathes of the US south-west, affecting nearly 23 million Americans and putting a strain on energy infrastructure.

Those experiencing the extreme heat are advised to avoid strenuous outdoor activities, stay hydrated, and wear sunscreen as well as light-colored clothing. For those who work outdoors, it is recommended to work early or very late in the day.

Those caring for vulnerable populations such as children, the elderly and people with disabilities should take extra precautions for them.

Heat is the leading cause of weather-related fatalities in the US. According to the US Centers for Disease Control and Prevention, “Approximately 1,220 people in the United States are killed by extreme heat every year.”