Haha, you're funny. If its cold storage it wont be a chip. And there is no way what the "doctor" would know what it is. There is no way you should rely on a chip for storing millions of dollars.
Either its cold storage and its not a chip or its a chip for accessing it often (not cold storage).
Not its not funny, there are many shady doctors out there that would do this. If people would start putting chips under their skins, storing digital money (not necessarly bitcoin but even bank account passwords), many mobsters would be interested in obtaining a list of these clients and then "visiting them" and then "extracting them".
http://www.creditcards.com/credit-card-news/rfid-chips-convenient-but-creepy-1273.phpIt is not as secure as you think.