Final answer:
While welding, materials that can easily ignite such as matches and lighters should not be carried in pockets due to the risk of fire or explosion from sparks or high thermal energy.
Step-by-step explanation:
It is not safe to carry matches or lighters in any pocket while welding because they can catch fire or explode. Welding generates a high amount of thermal energy and can cause sparks, which could easily ignite flammable materials. When welding, it's crucial to ensure your own safety by wearing appropriate protective gear such as welder's gloves and a helmet. This is not only to protect against burns from thermal energy but also to shield against high-energy electromagnetic radiation that can cause eye injury.