Transporting in winter

When I had to transport a baby to the vet, I just put them in a bag, and put them under my shirt for the drive over (but then my vet is just a mile from my house).

Deborah's idea seems to be the easiest solution of all for you!

I took a box and put a sheet folded up MANY times and put her in her bag and placed her in the box and had and thermometer it never got below 78 in that box, even with temps in the high 30's low 40's that day! I had a water bottle with me JIC I needed to fill it up at the vets it the visit ran long .... which it did ... So I had to use it to go get my son from school. She was never in direct contacts with the heat sorce but it provded a great ambiant temp in the box :)

Thank you all for your help!! I will be doing it again next week!

I got my baby when temps were below freezing. I kept him in a pillow case and put him in my coat when I was outside and did the same in the car until the temp in the car got warm enough where I could just keep him in the pillow case on my lap.

It was sort of an on-the-fly thing in case you couldn't tell! :P