I spent a total of 38 days in Gulfport with AMR before, during and after Katrina and Rita. We were staffing medical in a shelter during the storm, then running 911 after Katrina while AMR-Gulfport's employees attempted to get thier lifes back together.
Quarters consisted of anything from my truck, the shelter, a big army tent that collapsed during Rita, a cubicle in the billing dept (quite nice actually, backpack went on the desk, slept under the desk, put a blanket up for a door, a stash of the good MREs, and had A/C too!) I second AKflightMedic's post about the hygine, baby wipes first, then mandatory showers once per day (cold first, then hot). Food was MRE's if anything at first, then MRE's (funny part was that the ones AMR had were newer than the Guard guys' and they were trying to buy ours from us on the streets). After a few days, AMR had some of the casino chefs come and cook for us and it was damn good. They cooked 24/7, eggs, grits, bacon, sausage, hashbrowns, lasagna, spaghetti, salads, burgers, hot dogs, Steak and Potatoes twice a week!!!
AMR Gulfport was across the street from FedEx, and as soon as they were back up, had my mom (save the comments, she has a corp account) send down socks, a new pair of boots, extra pants and T-shirts and Kool-Aid mix.
Again like AK said, a mentally and physically draining experience, but the most rewarding thing I have ever done to help people who's entire lives have been washed into a 20' tall pile of debris with the rest of the town. What little they had they were trying to give away. We had cases of water/MREs to give out during our shift, and we had people who had just lost everything coming to us and asking if we needed anything or if we wanted some water. The people of Mississippi that we helped were phenomenal, an experience that I will never forget.