Hello,
A friend of mine had a friend who worked at one of the Disney parks as a princess. Apparently Disney characters aren't permitted to sweat (the princesses must return underground every 15 minutes in hot weather to have their makeup and wigs retouched). The actors in the full costumes (Pluto, Mickey, etc.) cannot remove the character heads for any reason, even in sweltering temperatures. If they vomit, they must do so in the costume and walk around in it. We can even extend this to Mike being a team mascot, wearing a duck or bulldog costume and getting beatup by fans, jumping around for six hours, etc. No matter how you look at it, wearing some 50-pound Mickey costume is a dirty job!