The State Fire Marshal and other local fire officials issued a warning Thursday about potential fire dangers during the holidays. Fire Marshal Jim Kenkel says live Christmas trees can be a major source of problems if not properly care for during the holiday period. Kenkel showed reporters a video of a test in which a tree was intentionally set on fire — it took four seconds for it to burst into flames. As the video continued, the entire room containing the tree was engulfed in flames. He says the tree ignites everything in the room and in 45 seconds it has used up all the oxygen and blacked out the room. Kenkel says you need to keep the tree watered and as fresh as possible. He says keep them away from heat sources. He says people often put trees by windows, but heat vents are often located near windows, and they can dry out a tree. He says you should close a heat vent if it is near the tree. Kenkel says never use candles or other things containing an open flame on a live tree. He says you should check the lights on the tree, and he recommends you use U-L listed lights. Des Moines district fire chief Matt Porter says a tree you buy on a lot will have a shorter shelf life than one you cut “live” at a tree farm. He says the trees on the lots can be shipped in from the east or west coast and have the potential to be a lot drier. Porter says a tree can become more flammable if it spends more time in your house. He says it seems like trees are going into homes a lot quicker than they used too, with some put up as early as mid-November. He says that lengthens the time they have to dry out. While candles were once a necessity for lighting, Ankeny fire chief David Burns says they’ve become a big item as decoration for the Christmas holiday. Burns says those candles are another big cause of holiday fires. He says you’re encouraged to make sure candles are on a noncombustible surface, that they’re place far enough away from combustible materials. Burns says you should always blow out candles when you go to bed and when you leave your home for any period of time. Burns says candles are an enticing thing for kids, but they pose a double danger. He says they should be kept up high and away from kids, as they present both a fire hazard and the potential for the child to be burned. The Fire Marshal and other fire officials also urge you to check your smoke detectors and be sure they have fresh batteries.