A record-setting heat wave scorched sidewalks, sports fields and schools across the state Monday, with dozens of school events postponed or rescheduled to cooler hours of the day. Students sweated through move-in day at the U dorms, popular downtown food trucks were sidelined in Minneapolis, and folks appeared to be staying away from the State Fair.

In Minneapolis, kids will be back in class Tuesday, despite a blistering opening day that saw teachers and students hefting bags of ice and hovering in front of fans in an effort to keep their cool.

Although temperatures should moderate some later in the week, no real relief is expected through the weekend.

The late-summer heat wave enveloped much of the Midwest. Schools in Iowa, Nebraska, Wisconsin, the Dakotas and Illinois let out early as temperatures crept toward the mid-90s — and beyond in some places.

The thermometer hit 97 in the Twin Cities, soaring past the previous record of 94, but the heat and humidity combined to produce a "feels like" factor of 106. A 96-degree reading was forecast for Tuesday, which would fall short of the record but still leave students, workers and athletes feeling like they were sweltering in 102-degree weather.

That had some Minneapolis parents thinking about keeping their kids home instead of sending them to classrooms without air conditioning.

"I have a second-grader and I'm going to assess whether he's going to stay home tomorrow," said Maria Fernandez, a parent at Kenny Community School in southwest Minneapolis, where only some spaces are cooled.

Another parent, Sandrine Hedrick, was weighing the same decision, noting that kids in her daughter's first-grade class were red and sweaty.

A thermometer there registered 97 degrees Monday.

After fielding questions from other concerned parents, the Minneapolis Public Schools announced Monday night that schools will operate on a regular schedule Tuesday but all after-school activities, indoor and outdoor, will be canceled.

"Parents have the option to keep their children home if they feel necessary. Absences and late arrivals related to the weather conditions will be excused as long as parents follow their school's procedure for excused absences," the district said, adding that building engineers are monitoring classroom temps throughout the day.

Minneapolis Superintendent Bernadeia Johnson said she had no second thoughts about going ahead with classes. "We have hot days during the year," she said. "I think that we'll be able to handle it."

Ken Mowll of Prospect Park was not swayed by district assurances that fans and extra water could keep kids focused on learning. He held his sixth- and seventh-graders home from Sanford Middle School Monday.

"Most of their friends did go to school. I can't imagine most kids are going to learn anything, and the poor teachers, they're the ones who are going to have to work through this," Mowll said.

St. Paul schools don't start until next week, but athletes are practicing.

Teams will meet for afternoon and evening practices but physical activities will be "reduced and less strenuous," the district said. All of Monday's afternoon and evening games in St. Paul were postponed.

School-start date debate

With pressure on for longer school years to boost learning, Minneapolis and other districts are now routinely opening a week before Labor Day, running the risk of having to cope with late-August heat.

School was called off entirely at 1 p.m. Monday in Springfield, Minn., where the school year started Aug. 19.

Minnesota law generally requires districts to start school after Labor Day, but Minneapolis and Springfield are two of many that have earned exceptions to that.

The start date is debated at the Legislature nearly every session, with those favoring the after-Labor Day start arguing it helps the resort and tourism industry, including State Fair attendance, said Rep. Carlos Mariani (DFL-St. Paul), chair of the House Education policy committee.

Springfield superintendent Keith Kottke said his district started last week in order to provide more instruction time in the school year before state tests in April and May. This school year there will end May 18.

"It's better to have a hot day in August than in late May," he added. "The kids are more motivated."

In annual surveys, district parents have supported the early starts, he said.

Hot moving day

At the University of Minnesota, residence hall students began moving in during Monday's heat.

Classes don't start at the U until Sept. 3, the day after Labor Day, a custom that is in part attributable to the fact that so much university property is used for State Fair parking, noted spokesman Steve Henneberry. The fair's final day is Labor Day.

Some workers in downtown Minneapolis and St. Paul had to change lunch plans as some food trucks opted to stay home for the day.

Maria Zarkha, a manager for World Street Kitchen, said the heat and competition from the state fair were two reasons the restaurant wouldn't be rolling downtown, along with the fact that Mondays can be slow.

She said managers wouldn't make a decision on whether to operate the food truck Tuesday until morning.

Misting stations are operating at the Minnesota State Fair, where more than 80 people had been treated for heat-related illnesses Sunday.

Four people had to be taken to hospitals. Sunday's fair attendance was down more than 20 percent compared with the first Sunday of last year's fair.

In Minneapolis, recreation centers without AC were closed and programs canceled.

The public works department suspended water shut-offs to residents and businesses who haven't paid their water bills, as part of several health emergency measures activated Friday.

The Red Cross, as part of that response, is keeping a downtown homeless shelter open round the clock, instead of closing it overnight, so that clients can stay cool, said Pam Blixt, preparedness manager for the Minneapolis Department of Health.

Twin Cities area hospitals reported scattered cases of heat-related illnesses — mostly dehydration or people with asthma who were having breathing problems — but said they weren't overwhelmed as of early afternoon Monday.

The heat wave is something of a late-course correction for August. Twin Cities temperatures ran well below normal through mid-month.

But the August average through Monday was 2 degrees above normal and likely to climb through the week.

Staff writers Jeremy Olson and Mary Lynn Smith contributed to this report. Steve Brandt • 612-673-4438 Bill McAuliffe • 612-673-7646