Final answer:
Heat detectors must be located within a certain distance of the ceiling, which is determined by multiplying the listed spacing of all points on the ceiling by a specific factor.
Step-by-step explanation:
The heat detectors must be located within a certain distance of the ceiling. This distance is determined by multiplying the listed spacing of all points on the ceiling by a specific factor. The specific factor depends on the regulations and guidelines set by the appropriate authorities. For example, if the listed spacing of all points on the ceiling is 2 meters, and the factor is 1.5, then the heat detectors must be located within a distance of 3 meters from the ceiling.