Thanks for all your input-interesting range of viewpoints! Yes DH is an adult, but with the stubbornness of a 4 year old at times. He'll know perfectly well when he's cold but will always push for that few minutes more to finish something. He also has a tendency to think that he's superman and still insists on doing things he really shouldn't- like lifting heavy items. We just bought new shower doors online and it was a two man delivery-only until package got past the front door! DH then manhandled 70kg through the house as he wasn't prepared to wait for our friend to help later on. My heart has often been in my mouth never mind this addition of working in sub zero temps. There probably is a significant degree of self interest, I don't want him to be unwell again obviously, but nor do I want to have to pick up the pieces should that happen. It was horrendous when he was ill before, I've never seen anyone as bad tempered as he was. He's had 2 additional chances already, not sure he'd get a third.