I would love the opposite, giving the option to click a "opt-out" button in case you need to do something real quick, but don't want medics to risk their lives. Also, if you would have to "opt-in" you would have to wait until the "you were killed by x" screen to go away before you were rezed (had some medics get to me before the screen even went away).
On a similar topic, they should make medics visible on the map to dead players. It annoys me when I'm halfway across an open field to rez a guy and he disappears to respawn. This would work well with the call medic/opt out button.
Medics are shown on the death screen as a + (yah it's kinda odd how its the same + above people's head while hurt, but non-medics don't see the + over hurt players)
Do they? I thought those were hurt people and it was showing them the same way it shows skulls on the death screen.
Yup, it's how I know to wait for a medic/respawn at a sundie, expeshaly with other classes. I do think I needs a different icon though, to save confusion.