This is a great idea!
My last crew chief has a very bad kidney disease requiring dialysis and hopefully soon a transplant. I also have heard of a member or 2 of associations around me going down. As a paramedic myself I see this as a great tool, often when we are faced with an unconscious person we know little to nothing about their history, the first place we look is in the billfold for pertinent, possibly life-saving, information.
If you could possibly post your guys' card I'd like to see it, and possibly could use it in our association or community as a whole, if its ok with you.