To avoid your candle glass from cracking, don't let the flame touch any part of the glass. Extinguish if the flame becomes enlarged, contacts the candle holder or begins to smoke. Do not move a candle when lit as the container may be hot. Discontinue use when 12mm of wax remains. Do not allow wick trimmings to accumulate in the wax pool. Place on heat resistant surface. Avoid using in drafty areas.