Dick Van Dyke, who played a chimney sweep in "Mary Poppins," and who made this profession a household word, was born on December 13th 1925. While he clowned around about being a "sweep," in reality it's serious business. Chimney fires are no laughing matters. While chimneys are made to withstand heat and smoke, burning wood creates a residue called creosote. Over time it collects on a chimney's inner walls (due to poor airflow or even burning overly damp or unseasoned firewood). Once creosote builds up in sufficient quantities, it can catch fire and burn at temperatures up to 2,000 degrees. That's hot enough to deteriorate masonry or to ignite surrounding combustible materials. It can flare up with surprising force too -- with a roar or a boom, or a sustained big "whoosh." If it's been a while since you've had your chimney checked (or if it's never been done), have it inspected soon -- for peace of mind and a safe holiday season. And that's the On The House tip for today.