'I gotta show you something," Jay Leno told the Tonight Show audience in December 2004. "You know this is the time of year you start to see all those safety demonstrations about Christmas trees and Christmas tree fires. I saw one. This is real. This is a fireman in Florida and he's making a video on Christmas tree safety. Take a look. I'll explain as it goes along." Leno grinned. He had a killer punchline coming. On the video, a fireman is circling a Christmas tree. He holds a red gas can. "He wants to get his point across," narrates Leno, "so, look, he's going to pour a little gas around the Christmas tree. Just to show you what can happen, OK. OK, he's pouring a little more gas. Now look. Look at this. He's putting even more gas around the tree. OK, OK. 'Cause he wants to show what can happen. OK, maybe a little more gas is needed. Then he realizes, that's only two and a half gallons, let me pick up another can." Leno has the audience roaring. "He pours a little more gas. Because he wants to get his point across that Christmas trees can ignite. So there's another two gallons of gas or whatever. OK, now watch this." The fireman returns with a lit candle, which he places on a crate next to the tree. "He gets a little disappointed here because he pushes the candle over and, oh, nothing happened." The fireman's hand is seen reaching down, nudging the fallen candle forward. "Now watch this. Yeah, I'll try it right ... Boom!" The tree explodes. So does the audience. The video fades and Leno appears again, basking in the laughter. "I love that piece of tape," he says wistfully. Jay Leno's not the only one who loves that piece of tape. The whole Tonight Show segment is available on the website of the National Christmas Tree Association, a lobby group that represents the growers and sellers of Christmas trees -- or "Christmas Tree Professionals," as the NCTA calls them. Christmas Tree Professionals are clearly bothered by official warnings about the hazards of Christmas trees. "At NO time can a real Christmas tree START or CAUSE a fire," the NCTA emphatically declares in the Holiday Safety Facts section of its website. "Christmas trees do not spontaneously combust." That is true. A Christmas tree cannot burst into flames without external assistance of some kind. A carelessly flicked cigarette, perhaps. Or a lit candle and several gallons of gasoline. According to the U.S. National Fire Protection Association, half of all Christmas tree fires start with faulty wiring, one-quarter are caused by a heat source being too close to the tree, and 15 per cent were lit by holiday candles. None involved spontaneous combustion. (Yes, these are American figures. But I assume Canadian Christmas trees are not dissimilar to American Christmas trees and that Canadians are as capable of gross stupidity as Americans. Those who dispute the latter point are asked to watch Don Cherry's speech at Rob Ford's induction.) But it is also true that a twinkling Christmas tree surrounded by presents and cherubic children is a living plant slowly dying -- a description rarely used by Christmas Tree Professionals -- and dying plants tend to dry out. If the tree is faithfully watered, that process can be delayed for as much as four weeks. But sooner or later, every Christmas tree goes dry. And when that happens, a Christmas tree undergoes a change in nomenclature. It is thereafter known as "firewood." Dry Christmas trees are so combustible that house fires in which they are the flash-point tend to be far more severe than others: One in nine house fires that started at the Christmas tree resulted in a death, compared to only one in 75 with different origins. Thus, while it may be true that Christmas trees do not START or CAUSE fires, as the NCTA says, having six feet of Douglas fir on the living room carpet does pose a real risk. And it is reasonable for public officials to tell people about it. Unfortunately, "reasonable" is not a word one would use to describe many public safety campaigns. Like corporations and politicians, officials trying to deliver messages to the public know that the public is constantly bombarded with information and one of the most effective ways of cutting through all that noise is to make your message as big, bad and scary as possible. Dousing a Christmas tree in gasoline takes things a touch too far, but many others apply the same attitude a little more subtly. "The holiday season is a joyful time of generosity and warmth," began a wearily typical public safety op-ed published in 2004. The author was Michael Brown. At the time, Brown was the undersecretary of Homeland Security for Emergency Preparedness and Response. He would later gain fame, of a sort, for his role in the drowning of New Orleans. And so, as one might expect, the flames in Brown's fireside dreams soon spread out of control. "House fires during the winter holiday season kill 500 and injure 2,000 people, and cause more than $500 million in damage," Brown wrote. The source of all this tragedy? "Holiday decorations, candles and Christmas trees. Fires caused by candles, for instance, increase fourfold during the holidays. Some 200 house fires occur each year where Christmas trees are the initial source of ignition." This stuff drives Christmas Tree Professionals crazy, and they have a point. No Christmas tree ever, in the history of Christmas trees, has been "the initial source of ignition." Still more imprecise is that statement about candles. It may sound impressive that there is a "fourfold increase" in fires started by candles, but what does it actually mean? If there are lots of fires started by candles, a fourfold increase would be serious. But four times an itty-bitty number is a slightly larger itty-bitty number. Without more information, the op-ed scares but does not inform. The bigger sin, however, is the lack of context for what look like large and frightening numbers. First, what's the time span we're talking about here? Brown doesn't actually say. However, the U.S. Fire Administration states that "the Holiday season is typically regarded as extending from late November to early January." That's a big chunk of the year. And we also have to consider that these statistics are for a nation of roughly 300 million people. Considering those dimensions, 500 deaths due to fire actually isn't all that much. Do the math: The average American's risk of dying in a holiday fire is 0.00016 per cent, which is about the same as the risk of drowning in a swimming pool and almost 50 per cent less than the annual risk of choking to death on food. And bear in mind that fires can and do happen at any time. We cannot assume that simply because a fire occurs in December it was caused by something holiday-related. In fact, there's good reason to think most fires during the holidays are not caused by the holidays. "Cooking is the leading cause of residential building fires in December," reports the U.S. Fire Administration, "accounting for 41 per cent of fires." Next comes "heat fires at 28 per cent, open flame fires at nine per cent, and incendiary/ suspicious fires at seven per cent." And other winter months? The breakdown is almost identical. Here are a few more statistics that will put a smile on the face of Christmas Tree Professionals. According to the National Fire Protection Association, roughly 85 million American households put up a Christmas tree. With roughly 200 Christmas trees catching fire each year, that means the chance of your Douglas fir going up in flames is about 0.00023 per cent. Taking all these facts into account, a reasonable public service announcement would go something like this: Keep the Christmas tree watered; make sure the lights are working; keep candles, space heaters and other hot things well away; pour another eggnog and forget about it. Granted, this message isn't nearly as attention-grabbing as Michael Brown's and it can't hold a candle to what that Florida fireman did. But it is accurate and that, as Martha Stewart says, is a good thing.