Dr Phil Kieran: My gym-going teenager has blisters on his feet 

Dr Phil Kieran: "To treat the hardened skin, soak it in warm water and gently use a pumice stone to remove the hardened layers. Be careful not to be too enthusiastic with the stone, as you don’t want to remove normal skin underneath the callus. Foot and hand creams that contain urea can also help soften the skin, which will help it remain flexible."

My teenage son works out at the gym five times a week. The intense exercise — mostly weights — and sweating have led to blisters on his feet and toes, some of which have hardened. I'm considering getting a pumice stone, but I'm unsure if it will do more harm than good.

Blisters, corns, and calluses are skin responses to friction or pressure. Most, if not all, of us will experience these at some point in our lives unless we are inactive, so it's a good idea to know what they are, how to prevent them, and what to do if you do have them.