The National Weather Service has extended an excessive heat warning through Saturday for most of the WISC-TV viewing area.
The high heat has been blamed for three deaths in Wisconsin and is suspected in a fourth.
Heat-related deaths were reported in La Crosse, Lone Rock and Janesville. The death of an Onalaska man is also being investigated as possibly related to the heat.
The heat has also caused highways across the state to buckle.
A heat warning was set to expire Friday night but it was extended because of hot conditions continuing into the weekend.
Dane, Iowa, Lafayette, Green and Rock counties are now under the warning until 7 p.m. Saturday.
"The cold front that was supposed to bring relief is slowing down and the cooler air is not expected to move into southern Wisconsin until later Saturday afternoon," said WISC-TV meteorologist Haddie McLean. "As a result, we will still have highs in the middle 90s. Extreme southern Wisconsin will have highs close to 100 tomorrow."
The warning runs through 2 p.m. for Jefferson and Walworth counties, while Marquette, Green Lake, Sauk, Columbia and Dodge counties will see the warning expire at 7 a.m. Saturday.
Six counties in our area are not affected by the extension, including Juneau, Adams, Vernon, Crawford, Richland and Grant counties. For these counties, the warning will expire at its original time of 10 p.m. Friday.