If you want to avoid a towering inferno this Christmas, you’d better hydrate your pines, according to the National Institutes of Standards and Technology. Avoid candles, and definitely don’t torch the thing yourself.

Part of the US Department of Commerce, the NIST works to develop better ways to measure things — like, for example, how likely a tree is to burst into flames. The verdict: much more likely if the tree isn’t well hydrated.

Christmas tree fires are rare, but they still account for roughly 200 home fires each year, destroying an annual $14 million in the process, the National Fire Prevention Association (NFPA) says. They’re deadly, too, killing an average of six people yearly.

So how do you prevent your tree from going up in flames? First off, definitely don’t light it up on purpose. That causes about a quarter of the Christmas tree fires, the NFPA says — usually in January. Since heat plus fuel equals fire, it’s also a good idea keep your tree and non-tree decorations away from hot things like candles and heaters.

Second: water your tree, and get rid of it when the needles start to crunch. Even a flaming book of 20 matches couldn’t spark a blaze in a well-hydrated, freshly cut Christmas tree. But just 61 seconds after flames licked the needles of a desiccated conifer, the tree was reduced to smoldering branches. The NIST did the experiment, so you don’t have to — no matter how you feel about the holidays.

The moral of the video is don’t let a dry tree ruin Christmas. Leave that to the deadly and dangerous toys you had been planning to leave under the tree, instead.