DENVER, Colo. (CBS4) – Truckers shouldn’t let Colorado’s record heat fool them. Starting Thursday state law says truckers must carry chains when they drive through the mountains.

The Colorado Department of Transportation already has signs along Interstate 70 warning semi drivers about the law. It requires them to have chains from Sept.1 through the end of May.

CDOT crews say the snow season isn’t far off.

“It’s not totally unusual. It can happen at a moment’s notice. I remember one personally around Sept. 12. It was pretty bad up here, so we like to remind them just to be safe.” CDOT tunnel supervisor John Wilson said.

The law applies to I-70 from Morrison to Edwards.

Truckers who don’t have chains face a $67 fine, which goes up if they cause an accident in the snow.