Mom's Green House!!

My Mom has one of those cool plastic zip-up green houses! I was so suprised when she showed it to me, because Donna and I were talking about these things. She has her tomatoe plants in it now. They're expecting snow later this week, so I'm wondering how they're going to hold up, as there's no heating in it. Perhaps the sun during the day will steam it up a bit and keep it warm? If you'd like to take a closer look at the green house, just click on the photo.