A brush with death is not so easily overcome, how many times will you fall before your body gives up on you?
Regular:
if you are healed back from unconsciousness you gain 1 level of exhaustion
Gritty mode:
if you are healed back from unconsciousness roll 1d6:
on an even roll you gain 1 level of exhaustion
on an odd roll you gain a grievous injury, that will require a number of days of recovery (which can be reduced by successful medicine checks)