HILTON, N.Y. — Superintendents across the region have been keeping tabs on subzero windchills as student safety is a priority. 

Many districts remained open on Friday despite the artic temperatures. There are several factors superintendents have to consider before declaring a snow day.

It's not just about snowfall totals or driving visibility. If temperatures and windchills dip to -25°, districts will and do close for the day. 

In the Hilton Central School District, 100 drivers were off to an early start on Friday to get buses ready and warm for the ride during this arctic blast. The district sent out an email to families Thursday night with some reminders to its 4,500 students to dress appropriately and bundle up. Only about 3% of Hilton students walk to school.

Superintendent Casey Kosiorek says he monitors the National Weather Service and local meteorologist reports to make what is sometimes a morning-of decision on whether to close.

"When we are talking about windchill, we are working with the Monroe County Health Dept," said Kosiorek. "They give some parameters. They do make a decision, but they help us make a decision given the fact that we can understand how long skin can be exposed at what temperature and what windchill that might be our students in danger. So right now, the guidance is -25 for 30 minutes if your skin is not covered. Oftentimes we see students who choose to wear shorts to school or not wear a jacket. I have students that attend the district as well, my own children, and I remind them that, 'yes, it is warm in the school, but if we had to evacuate the building or leave you would want to make sure that you are covered.'"

If you have to go outside in subzero temperatures, be cautious, bundle up and limit your exposure.