The alert has been raised by one of the firefighters who attended the blaze. Roger Wood, West Sussex fire and rescue service's head of community fire and road safety, said halogen lights in ceilings should be inspected to ensure they were fitted safely. The use of halogen downlighters fitted into ceilings has become popular in recent years. Many have been installed by DIY enthusiasts. But Mr Wood said the heat given off by the lights can cause roof insulation, or even timber roof joists, to catch fire if they were fitted too close. "Please make sure your halogen downlighters are fitted with fire resistant 'hoods' or that there is a sufficient gap between the lights and roof insulation or roof timbers. "Halogen downlighters do get extremely hot and they will set fire to insulation or timber if they are installed too close. "If a fire does start to smoulder, it is likely to be in an area that doesn't have smoke detectors, like roof spaces or ceiling voids. "This means the fire could develop without anyone knowing until it is too late," he warned. As reported in the Observer, two fire crews from Bognor fire station were called to a house in Waters Edge on Tuesday, November 27. They found the loft smoke logged. The source of the fire was found to be a roof joist which had almost completely burnt through. It was quickly put out. The fire is believed to have developed over a long period of time by the heat from a nearby halogen light radiating to the timber joist and causing a pyrolysis effect. This is the chemical breakdown of an organic material. The timber eventually dried out so much the heat from the light caused it to burst into flames.