One of the local SPCA's around here sold window stickers a while back that say in case of emergency please save my __cat / __dog so you could indicate that you have however many of either or to alert emergency personnel. I have those up in my windows, fwiw.
One thing that I didn't have to go looking for, but was (awesomely) offered to me a few years ago while I was going through cancer treatment was via my vet. I had brought my dog in for a thorough check up before I started chemo as I needed her as healthy as possible, and they vet said any time I needed help, they would be more than willing to kennel her.
I guess what I'm saying is that it cant hurt to ask your vet if they are willing to offer emergency kenneling in a medical emergency, as most kennels Ive used don't answer the phones after a certain hour. Especially if you live alone and don't have a lot of helpers around. Or don't have proper boarding options in your area.
Someday I hope to be the kind of person my dog thinks I am