I ran my game last night and it was awesome.... in a harrowing way.
The pcs had ended the session before trying to get a short rest, but had been interrupted. They kept trying and were interrupted again... and went in hot pursuit of the last bad guy, a ghoul, who had fled and fetched a vampire spawn. The pcs were all out of spell slots except for one of the druids (this is a party of five, four of whom are casters), and were pretty wounded, low on Hit Dice, and two of them already had had their max hps reduced by a previous encounter with a vampire spawn.
After laying the ghoul and spawn low, they were even more depleted- and almost tried to rest in the same location again, before wisely concluding that they'd end up killed that way. They retreated to a room that they could barricade, but something came along and tried to force its way in, then retreated when it failed, and they decided to get out before it returned with reinforcements.
They left the dungeon they're in and managed to get to safety, only to almost get killed by a random encounter before they finally got to get their rest in.
Two days later, refreshed and recuperated, they went back in to the dungeon, and that's pretty much where we ended, on the cusp of another encounter.