Radiation affects people's bodies in a number of ways.
To begin with, a very heavy dose of radiation bronzes your skin like a suntan, and it can burn you like the sun. It also makes your hair fall out, and knocks out your body's immune system. You would be unlikely to live for long. Heavy doses have been used to try to stop people rejecting transplants, but this is a very extreme form of treatment. They have to be isolated from any possible infection for a long time afterwards.