The National Weather Service issued excessive heat warnings across the central United States on Sunday as a persistent heat dome pushed temperatures and humidity to dangerous levels from Texas to the Upper Midwest. Heat index values were forecast to exceed 105 degrees Fahrenheit in parts of Kansas, Oklahoma, Missouri and Nebraska, with little overnight relief.

The Centers for Disease Control and Prevention has identified extreme heat as the deadliest weather hazard in the country. Emergency physicians and local health departments advised the public to stay hydrated, check on elderly neighbours, and recognise the symptoms of heat exhaustion and heat stroke.

Several cities, including Kansas City and Oklahoma City, opened cooling centres for residents without reliable air conditioning. Children, outdoor workers and people with chronic conditions face the greatest risk during prolonged heat events, according to the weather service.

The heat dome was expected to persist into the following week before a cooler air mass moved south. The prolonged temperatures have compounded pressure on hospitals already managing seasonal illness during peak mosquito season, when West Nile virus cases typically rise.