I was training a new guy a couple of days ago, we are on the roof and it's near zero, and I'm trying to be patient and let him figure it out, while at the same time keep things moving along, well it gets cold just standing around watching so I went downstairs, I wasn't there for 5 minutes, and here he comes, he sat the gun down thinking he was allowing the chems to work, and when he got back to the gun it was frozen, so I got it going again for him, had to drop it down and run water over it in the sink, he goes back up and he isn't there ten minutes till he lets it happen again. We’ll he gets done finally an hour after he should have "patience, patience, patience” and I haven’t seen him since, some people are just too soft.