Perhaps those passengers requiring essential medication should consider placing a small neck pouch/hip bag in the seat pocket containing these items, rather than placing them in the overhead locker.
I agree wholeheartedly. I do so myself. But airlines never even hint that passengers should do this, and all the many shops in duty-free don't sell 'take- on emergency pouches'. Why not, do you think?
If the aircraft does land at an airport, there should be a fleet of ambulances and trained medical staff heading in your direction.
You'd hope so, but there have been more than a few accidents where the emergency services have been slow to arrive - for example, the Asiana crash. The immediate priority is for the fire services to make the situation safe - the passengers are out of the aircraft and the initial need is to keep them out of the way. Getting them back to the terminal will need a bus or two, and the buses won't be sent until the situation is secure.
In conditions like the Delta incident, a passenger not in the best of health would suffer quickly without shelter or at least a coat.