metal the angle grinder produces a jet of flying red-hot metal. if that stream hits your pants, the pants are going to get burnt slightly. the sparks are typically not strong enough to leave more than a little burn, even on bare skin, but it's best to be prepared. wear old, reasonable thick work pants when using a grinder. if you use it a lot, consider buying a shop apron.
gloves: gloves protect the hands from the grit and heat produced by the grinder. one of the most common grinder injury is a burn caused by the operator touching a white-hot metal piece after the grinding is complete. gloves won't make 