I recommend any one - with special health needs or not - to fill out a Smart911 profile. Smart911 is an award winning, free service that lets you fill out a profile full of information that is associated with your phone number(s)and integrated with the 911 caller id system, so that if you call 911 from that number, they immediately have a ton of information about you. This info includes both personal information about you including your home address*, any particular medical needs, the layout of your house, info about anyone else in your household, including numbers of people, special needs, pets you have, etc.
Essentially the idea is that if you call 911 and are not in a position to give or access information clearly, they have it all there in front of them already and can act accordingly, making sure no one gets meds they're allergic to and making sure that everyone (even pets!) are accounted for.
It's not currently available everywhere, but it's rapidly expanding and you can fill out a profile to be ready for when it hits your area and request they bring it there sooner. You also have control over how much info you do or do not share.
*This is mainly to address the huge amounts of people who now use cell phones only. If you're calling from a landline, 911 can already look up the address associated with that landline and get to it. On your cellphone, they can track you vaguely by GPS but it very imprecise and unless you give your location when calling, they usually cannot find you, so the whole home address thing becomes really important.