Before the boys head into the Scorch, they're living in dormitories—just simple dorm rooms, where they all have beds and showers and such.
These dorms were created by WICKED, and they protect the boys from the outside world. The dorms are pretty much a little piece of heaven compared to the Scorch: they're sanitary, the boys are given pizza, and they can actually walk around without getting burned by the sun or attacked by a Crank. It's almost a mini-Glade, just without the Maze on the outside.
After the boys go through the Flat Trans, though, they enter the Scorch, which isn't exactly a vacation spot. The Scorch is pretty much a huge desert. During the day, the heat can burn you to a crisp, and the sun can make you go blind. When it's stormy out, the sky becomes a blanket of darkness, and lightning bolts crash into the ground like meteors.
Yeah, Disney World this ain't.
In fact, the Scorch "was a wasteland," to clear that one up (17.27). Just take a look at how Thomas describes it:
In front of him, a flat pan of dry and lifeless earth stretched as far as he could see. Not a single tree. Not a bush. No hills or valleys. Just an orange-yellow sea of dust and rocks; wavering currents of heated air boiled on the horizon like steam, floating upward, as if any life out there were melting toward the cloudless and pale blue sky. (17.28)
So basically, the Scorch is a barren wasteland with a mountain range about 60 miles north and a dilapidated city about 30 miles north. The boys need to go 100 miles north to get to the safe haven.
Yeah. Great. Sign us up.