If you are starting your first fire this year. First make sure your damper is fully open. Second when you feel cold air coming down the chimney. You need to warm the flu to change air flow so it's going up and out of the house instead of in your face. You can do this by rolling up news paper. Start one end on fire like a torch. Hold it up by the damper until you here a whooshing sound. That means it now should be drafting out of the chimney.