FALCON HEIGHTS, Minn. (AP) — Visitors to the Minnesota State Fair sought relief from soaring temperatures under misters Monday while some Midwestern schools dismissed classes early or called off sports practices. Highs approaching the century mark combined with oppressive humidity to made it feel like 105 to 115 degrees (40 to 46 Celsius) across the country's heartland, the National Weather Service said.

It issued heat warnings or advisories for large swaths of Oklahoma, Kansas, Missouri, Iowa, Nebraska, South Dakota, Illinois, Minnesota, Wisconsin, Michigan, Indiana and Ohio. “There’s going to be some records in play today,” warned Ashton Robinson Cook, a meteorologist with the National Weather Service Weather Prediction Center in College Park, Maryland. Several cities opened cooling centers, including in Des Moines, Iowa, where city buses were available to give people free rides to the sites.

Experts urged those venturing outside to drink plenty of water. “It is certainly steamy,” said Dr. Haley Taormina, an emergency medicine physician for Regions Hospital EMS, while treating fair-goers in Minnesota for heat illnesses.

By 11 a.m., she already had seen firefighters cut rings off two people's fingers after they became swollen from the heat and salty fair food.

Extra health care workers were assigned to the fair's medical stations, and air-conditioned city buses were parked nearby to give sweltering fair-goers a place to escape the heat. On the fairgrounds, Blake .