Most phones will usually survive such a drop. It all depends on how it lands. Phones with a glass back have double the number of ways that they can break when they fall, but it's still less likely to break than not. Drop it enough times and it will eventually break.

But the OP is talking about breakage due to thermal shock, not to physical shock.

The glass on the iPhone is actually quite resilient. The problem is the drop on one of the 4 corners (technically 8). At least that is my theory. All of the broken glasses I've seen have started at one corner and radiate out.