What is the hazard associated with installing insulation around knob-and-tube wiring?

Installing insulation around knob-and-tube wiring poses a significant hazard due to the risk of overheating and potential fire. Knob-and-tube wiring was designed to operate without being enclosed in insulation, which allows for proper air circulation to keep the wiring cool. When insulation is applied around this type of wiring, it can trap heat, causing the wires to overheat. This can lead to insulation deterioration or even ignition of combustibles in close proximity, creating a dangerous fire risk. Thus, choosing to insulate around knob-and-tube wiring disregards these safety factors, making it a hazardous practice that should be avoided.