I tried to get a boil going outdoors on a turkey fryer when it was in the mid-20s and quite windy. Not a mistake I will be making in the future.you would have been fine:)
I was successful in brewing in the cold with the turkey fryer by using it in my detached garage with the bay door and entry door open so there was a good draft. I sat in my car in the driveway and watched to make sure nothing bad happened. Not sure if the fumes in the garage would have been bad enough to cause harm to me but I didn't feel like taking the chance.
I brew in the garage with the bay door open about a foot and the service cracked open. I have a co monitor and it's never gone off