Sadey and the snow

I took Sadey outside with all the snow and she ran around outside for a minute then feel over. I walked over to her and picked her up. Then I went to work. A few hours later my husband took her out and her little legs locked up and she fell over, so he walked over and picked her up. then he called me at work and told me about this and I told him that she had down the same thing with me. So then he put out a puppy pad. She will not us it. So I took her out this morning and she peed, then was smelling around , then she looked at me and started to fall, I was close to her so I got to her before she fell, and now she has been sleeping next to ever since. I do not understand why her legs lock up with this cold. She will not let us put a collar on her or anything we try and she freaks out. The one time I decided to leave the collar on her and make her get use to it she has a score on the back of her neck about a inch long. So that went out the window. it is the same thing with a harness and anything you can put on her. John seems to think that people we got her from (they had kids) put things on her and it hurt her and she thinks it is going to hurt her. But she is great with kids, she wants them to play with her and if the baby next door is over and she starts to cry sadey will come get me and get my attention and then run to were the baby is. Like she is telling me she is crying. I could not be more happy that we got this dog. She is amazing and John and I both adore her.