[jfkebwjsbx]

Depends on the disease.

Something like a stroke requires immediate action (say, within 2 hours) to be able to use the best treatments available. Living very far away from a good hospital makes your survival chances quite lower.

For Covid-19, as far as I read, some people have gone to the hospital (already having trouble to breath) and died after a few hours. But those seem extreme cases. Normally you would have a couple days to go to the hospital from the moment you realize something is odd.

[kortilla]

Life flights put most rural places in the US within those time bounds.

[jfkebwjsbx]

Yes, but those bounds are not binary. The faster you arrive, the higher the chance survival (specially for things like strokes, arriving in 30 minutes is way better than in 2 hours).

Then there is the issue of cost for that flight and the poor state of healthcare.