Whether to hold school tomorrow may be a tougher call for Iowa superintendents than it was today.

“It’ll be a dilemma, there’s no doubt about that,” says Dan Smith, executive director of the School Administrators of Iowa. “Hopefully the wind chills won’t be as severe tomorrow.”

The statewide wind chill advisory expires midday Tuesday, meaning temperatures should be warmer at school dismissal time. Smith expects many schools to announce classes will start two-hours late — and then cancel if the wind chills persist. Getting students safely to and from school is the concern, according to Smith.

“Walking to school or waiting for a bus or even the issue of bus maintenance,” Smith says. “Buses certainly are better than they were many years ago, but there still is the issue with diesel buses — and most schools have diesel buses at this point — of the fuel jelling up and stalling. You could have the issue of a bus being stranded some where a ways away from where you would be able to get out to them very quickly.”

Experts say in current conditions frost bite on exposed skin can set in after just a few minutes. Smith, who spent 25 years as a superintendent, “has a lot of empathy” for school officials who’re making the decision to cancel classes.

“Oftentimes young people don’t use the best judgment in terms of wearing or keeping on hats and gloves and those kind of things,” Smith says. “While we can’t protect against any kind of potential hazard, when the wind chills get this dangerous, safety is the best decision.”

The school year in Iowa is a minimum of 180 days and schools will have to make up any cancelled days.