He would die with that kind of protection.
There were some inaccuracies in the book and the plot. But it was a great book anyway.
That list of doom:
On a reddit Q&A, one fan asked Weir if such withering storms were possible on Mars.
Weir's answer: "No. Mars’s atmosphere is too thin. This was a deliberate concession to
drama that I made because it’s a man-versus-nature story and I wanted
nature to get the first punch in."
2. Cosmic Rays (Radiaiton Poisoning)
(ANSWERING YOU HERE)
After being left alone on Mars, Watney makes his way toward the Schiaparelli crater. Spending that much time on the planet would expose him to a dangerous, and probably fatal, amount of cosmic rays, if not for his handy (and fictional) radiation blocker.
"The book has a completely fictional material that blocks radiation. No such thin, flexible, light radiation shielding exists in the real world" —
Andy Weir, author, 'The Martian'
NASA limits its astronauts to between .8 and 1.2 sieverts of lifetime radiation exposure, which would raise the lifetime risk of cancer by 3 percent. Because the sample size of astronauts who have spent a considerable time in space is so small, the exact health effects of cosmic ray exposure is clouded with uncertainty.
The most effective shields against cosmic rays, like water or liquid hydrogen, tend to be heavy and not portable—meaning they’re suitable inside the walls of a space capsule, but impractical in a spacesuit. Researchers are working on plastic cosmic ray shields, but haven’t gotten there yet.
3. Producing Water
Watney mixes hydrazine, a toxic substance usually handled by people in hazmat suits, and oxygen to make drinking water. The admixture also produces ammonia which is poisonous.
“Yes, very toxic. I didn’t know that at the time. Had I known, I would
have had him wear his EVA suit during the process,” Weir replied during the Q&A.