Nah it's not, I do it all the time. Anyway, I think I would wait until I was changed before searching for the kid. It's not like they can get far in a shopping center or swimming pool.
I'll shout "somebody grab that kid. 10$ if you stop him from running away". Some old man who wants money will comply. Heck you needn't even promise money, some helpful old man will help if ask them to. Unless those are unhelpful hand-less old men in the hallway and the room is soundproof or something. Or i will hang myself to death with the towel, because my son has ran away from me and i'm too embarassed to run out half-naked among old men and children.