Look: Napa Valley

Feel: Canada

Arctic air from Canada will make Thursday, Friday and Saturday night temperatures dip into the mid-20s, causing government agencies to wave red flags about potential dangers to vulnerable populations.

Thursday night lows will reach 29 degrees. Friday night lows will reach 25 degrees. Saturday night lows will reach 28 degrees. Low temperatures will gradually reach the mid-30s by Monday night.

It’s a time when it’s best to dress warmly and not stay outside very long, officials say. Prolonged exposure to the cold night and morning air could bring an unwelcome bout with hypothermia if people aren’t prepared for it.

Perhaps the best way to deal with Canadian air may be to act a little more Canadian.

That means dress in layers, take care on possibly icy roads and be nice — make sure that elder family members and neighbors have good heat sources, outdoor pets aren’t left to fend for themselves and children are dressed properly when they’re outdoors.

“If kids and older people seem to be a little bit lethargic, pay attention,” said Dr. Karen Smith, Napa County public health officer.

It’s also not a good idea to try to supplement the usual heat sources with a barbecue.

“Don’t ever bring any kind of barbecue device or any object that is used to heat something outdoors inside,” Smith said. “You can actually die from carbon monoxide build up. You won’t notice it. In fact, what happens is you fall asleep. When carbon monoxide deaths occur people die in their sleep.”

Road trips to isolated areas are also not the best idea right now, Smith said, but if motorists must make the trip, they should make sure someone knows where they are going, fill up on gasoline and take extra care the vehicle is in good working order. Blankets are handy in case the car breaks down.

John Feerick, a meteorologist with Accuweather.com, said as cold as it’s going to be in Napa, 1949 was probably colder. That was the year nearby Santa Rosa — the only low record for this time of year in the region he knows of — set a Jan. 12 record low of 21 degrees.

“Once we get past 10 a.m. or 11 a.m. in the morning, most places will see temps in the 40s because we will have some sunshine each of the next couple of days,” he said. “Friday and Saturday morning are really the coldest mornings.”