Oh, you can use hitpoints and clocks however you feel best, no need to die!
I don't use clocks in any same manner as hitpoints myself. (i.e. I can 'heal' a few hitpoints, I don't allow a clock to 'untick')
For me, the best use of a clock is as a time to thing happen. one way flow. that thing either happens (clock ticks last tic) or that thing not happen (something made clock irrelevant or impossible, kinda like disarming bomb.)
I realize those things can be done
(like making a bomb clock count backwards for a bit, but its still really just about if bomb blow or not), but I don't feel the need to mush those mechanics together.