We rushed out to the lab to see what had happened. The door to one of the warming ovens was on the floor on the opposite side of the lab from the oven it came from. My samples were spread all over the lab. The glass door was very warm to the touch, so clearly the oven had been on. The thermostat on the oven had created a spark that had ignited the acetone fumes from the samples. I was not amused, since a couple of hours of work had just gone up in smoke.