Apologies if this is slightly off topic but I think it may be of interest anyway as well as being relevant.....We had deep fat fryer that after being switched on burst into flames causing copious amounts of smoke and the evacuation of the kitchens. The fryer was fitted with a thermostatic cut out device but since the fryer was empty of oil at the time the trip-out device didn't stop the unit from heating up - it seems some trip out devices only work when oil is in the pan. The small amount of residual oil in the pan is what became heated and subsequently ignited. The fire was successfully put out and normal kitchen operations were able to resume fairly quickly. Following talks with the manufacturer I understand that it is usual (not sure if it's a legal requirement) to have a thermostatic cut out fitted to fryers but just be aware that it is possible that these devices may only function when the unit is full of oil and not when empty. It appears there is nothing (other than human diligence) to prevent some units being switched on and being left to heat up when empty! Needless to say our systems and procedures have been amended to prevent this situation from arising again.