Short, readable, punchy, and unpleasant. Let me be clear. There has been some sort of hard-crash apocalypse; nuclear at least ("a minute outdoors is a day less to live") and probably biological as well (not a cockroach or blade of grass in sight). Our "hero" knows nothing of this, nor anything else, including why he is paralyzed from the waist down. On the up side, he is mysteriously immune to radiation sickness. The people who are waking him from cold storage know this, and need him to do them a favor -- outdoors -- despite his handicap.
It doesn't end well. Doesn't start very well, for that matter. The protagonist tries to strangle the first person he sees (on instinct), and has little control over his destiny thereafter. What decisions he does make are wrong. We wind up with few answers and no happy ending in sight, unless you count a few strands of regenerating algae in a stream. If you're okay with that sort of story, I recommend the book -- the telling is compelling. If you're like me, you'll close the book and wish you'd never opened it, while being reluctantly impressed anyhow.