It's not likely your chickens both went broody in one night.
Kick their butts out and block those nest off after laying is done for the day.
Put yourself on a down jacket, (go to big 5 if you have to), and step outside to see how toasty you are.

Those girls are fine! They are wearing down jackets.
Sleeping in the nest box is a bad habit and can cause your eggs to be poopy.

The amount of poo on my boards is crazy how much they do during the night. Broodies don't poo like that, they hold it until they go out for their daily ritual.
Yes, I remember those balmy 70+ degree Christmases of So Cal... shorts and t-shirt. So 42 seems cold. The girls may stay in to avoid the rain for a little while. But they will be up and about before long (probably, seems animals and kids will do what they can to make a liar out of me sometimes).