It's always been a horror story. Imagine those scenes in movies where people try to enter a secure place or escape captivity by going through narrow pipes or metal tubes where there is a flame going to come through, or a fan moves at regular intervals that can cut people to pieces, and they manage to make it through everytime. Real life is more dangerous, and people are not successful every time they try to make it through such dangerous entrances. One of the perennial questions about the concept of Santa Claus is about coming in the house through a chimney, and whether Santa would get stuck inside the chimney or if the fire was lit, then it would get real dangerous. In a tragic case, a real life situation ended up where a suspected thief tried to enter the house through a chimney, got stuck, and died when the house owner lit a fire (without knowing that there was somebody stuck in the chimney). What a horrible way to die, although it might be the gases passing through the confined chimney rather than the fire or heat itself (link to article):
The man appeared to have climbed into the chimney during the night while the owner was away and then became stuck, according to the Fresno County Sheriff's Office. The owner of the home in Huron lit a fire in his fireplace on Saturday afternoon but then heard a man yelling inside the chimney as the house filled with smoke, the sheriff's office said in a statement. The homeowner tried to extinguish the flames but firefighters who dismantled the chimney during a rescue effort found the suspect dead inside, the sheriff's office said.