Doing this in cooler/colder weather would be best, IMO. But, it has been done successfully, but not sure what the temps were outside at the time. You really need an older generator that emits a lot of pollution. You won't be breathing just CO with a generator, either. There are lots of other nasty stuff that comes from burning gasoline that you'll have to endure for however long it takes. The newer generators are being manufactured to be less polluting, called CARB compliant, and have lower CO output than older ones. Look up a movie called Conrad and Michelle, which is based on a true story. It won't give you details regarding equipment, but it shows the scenario you are talking about. It was a pretty good movie. Charcoal would be better, IMO.