For some people, just protecting the hand is enough, but many heat resistant gloves also offer guards for your forearms. Most sleeves aren’t as durable as the gloves themselves, because you aren’t going to intentionally get into contact with a hot surface with your forearm. Typically that contact comes because of an accidental bump or brush on a surface. However, some forearm shields are made with thin layers of kevlar to protect your arm while also making sure you still feel the heat and move away from it. If you are going to be reaching into something, such as a deep fireplace, or will be dealing with flying embers or fire flare-ups, then arm protection might be needed. If you are just going to be interacting with a hot surface momentarily, and not exposing your arm to the heat, then you will not require any protection above the wrist.