The hospital was an utter nightmare. Such a simple phrase would be a hyperbole, but that was not so, as what went on in this hospital was the stuff of nightmares. It was like something one simply couldn't wake up from, and the only safe place in the whole building was the roof, and that was simply because the surgeon known as "Mad Hat" had fashioned a few molotov-esque explosives using flammable antiseptics, medical bandages, and a lighter he had received as a christmas present from his now late wife.
Of course, a few flammable explosives weren't going to stop the legion of the undead storming the hospital, so Nathan simply had to improvise, personally crashing gurneys along the stairway to slow down the horde climbing up the stairs, and then eventually piling everything he could in front of the hospital door. Of course, Nate knew that this wouldn't be a permanent hiding spot, as he would eventually have to come down, but he had all of that taken care of as well. He would simply have to take the rope he had fashioned out of bed sheets, tie it around his waist, crash through one of the windows, and then fight his way to the garage, where his car had been parked.
Of course, things were easier said than done, but Mad Hat didn't sit around and do nothing while he bided his time. Nope, instead, he made liberal use of his scoped magnum, and simply picked off a few of the zombies that would no doubt hamper his escape.