They did not burn kerosene, it was a 50/50 mix of methanol and isopropyl alcohol. I suspect you are referring to charcoal heaters in regard to the 30 minute wait period. Frankly, if I would have had to wait 30 minutes to refuel charcoal heaters I would have been working OT. There was a rule two people had to be present when refueling charcoal heaters.
