At what temperature do light bulbs begin to swell or distort?

The point at which light bulbs begin to swell or distort is generally around 900 degrees Fahrenheit. This temperature is critical because it represents the threshold at which the materials used in the construction of typical incandescent light bulbs, primarily glass and filament, are subjected to thermal stress. At this temperature, the glass can start to lose its structural integrity, leading to deformation.

Choosing this temperature is important for safety considerations in fire investigations, as knowing the material characteristics and how they behave under high heat can help in determining the origin and cause of a fire, as well as assessing how a light fixture might have contributed to the incident.