Minnesota simmered like deep Texas on Friday under an excessive heat warning, with temperatures pushing triple digits in the Twin Cities and the southern portion of the state.

Friday's high at the Minneapolis-St. Paul International Airport was 99, a temperature that hung around for much of the afternoon and that, with the humidity, had a "feels like" value of 110 degrees, according to meteorologist Paul Douglas. The temperature remained in the 90s into late evening.

The only respite was a gentle wind of 15 miles per hour, and even that felt like a hair-dryer blast.

The state's highest heat index values were recorded in Cambridge and South St. Paul, where it felt like 112 degrees. The heat index was 109 in Red Wing, 103 in St. Cloud.

The recommended antidote to the heat and sun was shade, water and air-conditioned buildings. Ross Carlyon, a weather specialist at the National Weather Service's regional office in Chanhassen, recalled an old Weather Service saying that was apt Friday: "Trade a lawn mower in the sun for a lawn chair in the shade."

The steamy conditions were expected to break Saturday, with a strong chance of thunderstorms in the afternoon. Highs Saturday through Tuesday will be in the 80s. The July 4th holiday on Wednesday will creep back up into the 90s.

None of those days will be as hot as Friday, though. It brought warnings about everything from driving to dogs and drinking.

In Minneapolis and St. Paul, city recreation centers without air conditioning closed and residents were encouraged to visit lakes, pools and park buildings with AC. Both cities canceled outdoor fitness activities.

"It's easy to get really sick, really fast," Carlyon said, urging people to slow down and take in fluids — preferably water.

On Friday evening, HCMC spokeswoman Christine Hill reported that the Minneapolis hospital had seen at least two people for heat-related maladies. Both were treated and released, she said.

The Minnesota Department of Transportation warned drivers to be on the lookout for pavement buckling. In extreme heat, "roadway segments expand and have nowhere to go but up," the agency said.

A segment on southbound Interstate 35E did just that near Eagan on Friday afternoon, complicating the drive home.

MnDOT said drivers who see buckles should slow down, move to another lane and call 911 to report the problem.

As if that weren't enough, MnDOT also warned that numerous roads across the state remain flooded. For updates on those and construction closures, travelers are urged to check for real-time updates at 511mn.org for potential trouble.

Carlyon said that under extreme conditions, the body can spiral into heat stroke with little warning.

"When you're working outside, especially in this kind of weather, you tend to dehydrate real fast. As you dehydrate, your body doesn't cool," he said.

That can lead to feeling confused or dizzy and ultimately a collapse, he said.

Complicating matters for Minnesotans is that unlike Texans, they're not accustomed to this kind of heat.

Douglas called the heat situation "Saudi Arabia with lakes" and a "danger zone." On Twitter, he wrote, "Don't even think about leaving the kids (or pets) in a car today, even for a few minutes."

He called Friday's weather "the unfortunate offspring created by a shotgun wedding of Arizona heat and Florida humidity."

Alas, it wasn't the hottest of days. The record for June 29 was set in 1931 at 102.

Rochelle Olson • 612-673-1747 Twitter: @rochelleolson