Frosty the Snowman won't be the only one wearing a smile in the next few days.
With the National Weather Service predicting this week could bring the longest cold snap to Colorado since December 1998, many schools may be forced to close.
Along with road conditions and snowfall, district weather policies also take into consideration frigid temperatures and wind chills.
"Our concern is for walkers, kids waiting for the bus and students standing outside before school starts," said Devra Ashby, spokeswoman for Colorado Springs School District 11.
Frostbite doesn't take long to nip exposed noses, ears and fingers, said Chris Taylor, a supervisor, bus driver and driver trainer for Durham School Services. The company provides bus service for Woodland Park School District RE-2 and some charter schools in Colorado Springs.
"Kids don't need to be standing out in that kind of weather," he said.
A severe wind chill warning sets off the bell for Jed Bowman. The superintendent of RE-2, which serves students from Woodland Park, Divide, Florissant and other areas of Teller County west of Colorado Springs, said a warning alone can be enough for him to consider delaying or cancelling classes.
"Our buses struggle around 10 below zero," he said. "But our No. 1 priority is student safety."
Two years ago, Bowman said he canceled school when the wind chill was minus 30 to 40 degrees.
"We do not have a formal policy - we use the National Weather Service's Wind Chill Warning as a major guide," he said. "Our challenge is the vast differences between our communities."
That's also a difficulty for Falcon School District 49, which covers the eastern plains.
"We know that temperatures can widely vary, so in one part of our district it could be minus 15 and in another, it could be 10 above," said spokeswoman Stephanie Wurtz. "Ultimately, we err on the side of safety for students, especially when it comes to cold temperatures."
The district refers to the National Oceanic and Atmospheric Administration's wind chill index for decision making on how cold is too cold for school to be in session.
"Around minus 16 or so, frostbite can occur after only 30 minutes of exposure - that's really our threshold," Wurtz said. "However, other factors, such as snow and ice, could mean we close due to the cold when it's above minus 16."
D-11 also has been known to close because of temperatures, Ashby said. But just because it's cold out, doesn't mean the wind chill is considered dangerous, she said.
"We use a matrix of temperature and wind speed. Two years ago we closed for a couple of consecutive days because of extremely cold temperatures."
Parents sometimes get frustrated about closures or delays, but district officials say they do the best they can to gauge how a day will turn out.
The timing is tricky, Ashby said. D-11 sends crews out at 3:30 a.m. to check out conditions.
"We also take into consideration what other districts are doing and the city's snowplowing, then we make the call around 5:30 a.m.," she said. "There's a fine line because you can't be wishy-washy."
If schools are open in the coming days, though, they'll be ready for the expected arctic blast. Facilities crews will work to prevent frozen pipes, according to officials.
D-49's bus drivers will report a little earlier to make sure the buses are warmed up, said transportation director Gene Hammond. Engine block heaters will run 24/7, and coolant heaters will be activated, he said.
Many buses will rely on automatic tire chains for additional traction on ice and snow. The handy devices drop down and slide over tires with the flip of a switch from the driver's seat.
They've dramatically decreased how often Durham School Services' 35 buses slide off roads or get stuck, said Taylor.
"We do mostly rural routes, on dirt roads with culverts from 1 to 4 feet deep and no curbs," he said. "The drop-downs help quite a bit to keep us from sliding."
They aren't intended for speeds of more than 25 mph, though. Drivers must manually install regular tire chains then, which take a while and can make buses run late, Taylor said.
In D-49, 46 of its 48 school route buses have the automatic chains, which Hammond said helps drivers when they don't feel comfortable with just rear-wheel drive.
"The length of time of the cold makes this coming storm out of the ordinary - it's more concerning when it's a longer-term event," he said.