Three of us were out this weekend in the Sierra at a little over 6300', got down to 6F over night. I had to prime my old kerosene burning Optimus 111T using alcohol, really surprised this AM how quickly the alcohol lit. It still took two primes to get the stove going, but that was ok. I used it as a hand warmer, while I ate and listened to my old Primus 71 roar away melting snow and boiling water for my instant oatmeal. I have read the comments about alcohol, so now I have first hand experience. I've gotten into collecting vintage camping/bping stoves starting last year, so all there "old relics" give me something to look forward to on trips and see how they did things years back.