I wonder if carrying a medical info card on one's person really helps all that much. A while ago I discussed this with a paramedic and a nurse working in the ER. Both said that no medical information found on the patient/victim, unless issued officially and clearly belonging to the person in question, would be taken at face value.

For instance, even if you're wearing a blood type tag the paramedics are required to double check first before giving transfusion. At least that seems to be SOP around here. The only exception being service personnel on duty carrying official tags or info cards, or civilians with a serious condition (such as diabetes or epilepsy), again carrying officially issued armbands and/or tags.

Apparently, there have been instances when people were wearing cards with information that was either incorrect or pertaining to a different person. Hence posing a serious liability (not to mention a potential lawsuit these days).