1:03 p.m. Because extremely hot, humid conditions are expected to persist for four consecutive days — through Thursday — the National Weather Service has upgraded the heat advisory that had been in effect for Lawrence and surrounding areas to an Excessive Heat Warning.

The warning has been extended and is in effect until 7 p.m. Thursday and covers virtually all of eastern Kansas and western Missouri.

An excessive heat warning is only issued when high temperatures and humidity are expected to combine to make it feel hotter than 110 degrees outside.

The National Weather Services urged everyone to avoid prolonged exposure to the heat, if possible.

6News Meteorologist Alex Harrington said that heat waves are responsible for more direct deaths in the United States than any other weather-related hazard, except extreme cold.