At what minimum temperature will a heat sensor label on a metal ladder change color?

The heat sensor label on a metal ladder is designed to provide a visual indicator of elevated temperatures that could compromise the integrity of the ladder. This label typically changes color at a minimum temperature of 149°C (300°F).

This temperature range is significant because it can indicate to firefighters and other emergency responders that the ladder may have been exposed to heat levels that could affect its structural integrity. If the metal ladder reaches or exceeds this temperature, it might weaken, bend, or become unsafe for use, which is critical information in a fire situation. Having this clear temperature threshold helps ensure safety during operations where ladders are employed.