Claudia Winkleman is a British TV presenter, radio personality and journalist. She's also a mother of three who went through every parent's nightmare during Halloween of 2014 when her 8-year-old daughter, Matilda, was badly burned after her Halloween costume caught fire. The cause of the fire was a house that used real candles in their jack-o-lantern, which a part of Matilda's dress brushed up against.
There are two big lessons to be learned here. First, Halloween costumes are not regulated by the same kinds of safety standards that regular children's clothing is. The more inexpensive ones in particular tend to have a lot of synthetic materials, many of which are significantly more flammable than normal clothing. This is the reason that Matilda was burned so seriously. Second, the overall potential fire hazard of a jack-o-lantern has been established for some time, but this just further emphasizes the need to use safer alternatives like electric tea lights or even LEDs, neither of which are prohibitively expensive.