It is a problem if your are trying to paint below freezing. Acrylics are water soluble, like watercolor. Try working from the comfort of a heated truck or automoble. You can turn in on every so often to warm things up.... and don't forget the cup holder! You just need to limit your paint colors on your palette and the size of your painting surface, board or canvas. If you are left handed, you can sit in the passengers side and put you palette behind the steering wheel. I have painted plein air watercolors for years in below freezing snow drifts, warm and toasty in the car. Remember to put down a drop cloth, or take the SUV or Van and paint in the back. Or, move south y'all.
Some of my fastest and exciting paintings were done in the cold. I suggest standing or sitting in a protected area from wind, but make sure you are in the sun (but not your canvas). It is surprising how warm you will be in sunshine and how much colder it gets when the clouds show up.