Im a hopeful applicant and i am not sqemish one bit, but i would be wary (safety sense) of any blood that isnt mine in a clincal situation.
I think tolerence comes with experience, medicine is definately not a glam job. I am lucky that my life has afforded me this experience. I am a farmer so i get **** and pissed on most days, have calved literally hundreds of cows with ruptures, ceasars, many a breached bovine baby. In my degree (Anatomy Queens) i have dissected a human head to toe, really useful having a cadaver as so many med schools dont use them!
NB know what your letting yourself in for! apparently there is at least 10 (of 300) students who throw up during first dissection in our med school, the formulin needs getting used to.