On my (lineage) phone I can press "emergency " instead of typing the pin, and then reveal emergency contacts and medical information I choose to put there (allergy's, medication etc)

I don't think I installed an app. I assume its a aosp feature.

Use a medic alert bracelet if you need something like that. EMTs are trained to look for it. They aren't going to derp around looking at your phone.

Maybe not exactly what you're looking for, but this app could be useful someday: https://github.com/ligi/SurvivalManual It's also available in F-Droid, but didn't receive any updates for 4 years. It's basically an easily navigatable pdf that tells you what to do in a survival situation