Loosing babies

Creamcicle...my sport Lionhead doe had 5 babies early this morning or very late last night...she did not pull enough wool and 4 of them got too cold and died..1 is still alive..I brought it in the house to warm it up..it was almost dead so I don't know if it will survive or not...I checked on her at 11:30 last night and she had not had them but then I went to bed..I went out at 8:30am ..by then it was too late...there were 3 Bew's and 2 Vm's...the one that is still holding on is a Vm....I really thought it was warm enough in the barn with the heater but I guess I was wrong....she didn't pull enough wool.. ..the one that lived is warm now and active...so maybe it will survive..I put the heater next to her cage and I am hoping she will feed the little one...