Which comb should you NOT use on blow dried hair or electric thermal iron?

Using a metal comb on blow-dried hair or with an electric thermal iron is not advisable due to the potential for heat conduction. Metal can easily transfer heat, which can lead to damage for both the hair and the comb itself. When using high-temperature styling tools such as a thermal iron, the metal can become excessively hot, increasing the risk of burns when in contact with the scalp or hair and also causing hair to become frizzy or damaged due to high localized heat.

A plastic comb, fine-tooth comb, and round comb are safer options for such styling because they typically do not conduct heat as metal does. Plastic combs can withstand a certain amount of heat without deformation, while fine-tooth and round combs serve specific styling purposes without the risk of direct heat transfer, making them more suitable for use in these scenarios.