[cypher]

I have to go to the vet in the snow & sub zero temperatures today too, I put plenty of substrate in the carrier, put the carrier on the radiator for a while before going out (before I put my ham in!!) to warm it through, then I put it into a large shopping bag with a semi warm heat pad (not fully heated as that's too much) in the bottom with a fleece blanket on top of that then put the carrier on top of all that, you could partially cover the top with a blanket too but make sure there's still plenty of ventilation.