Please do not treat them this way. They do not grant access to your account. Print many copies of your recovery codes and spread them around. Wallet, home, car, parents' house, etc. It doesn't matter if they get stolen or whatever, again they don't grant access to your account, and they can be revoked at any time.
I know that educating people about this is not a scalable solution to the problem of people getting locked out of their accounts. But maybe it could help you, reader of this comment, if you someday need recovery codes.