Dialysis is a special concern, and for residents in Houston, already approaching crisis. As NPR reports, it’s important for patients with kidney failure to receive dialysis services every two to three days. But local dialysis centers are struggling with the demand, and with shortages of qualified staff, since several nurses who’d normally work in the centers are themselves displaced by the flood. And while companies like the DaVita Med Center and its locations around the Houston area are working around the clock to meet the area’s dialysis needs, as patients go longer without regular services and appointment reminders, the only solution to keeping them alive may be taking them to one of the area’s hospitals.

And the hospitals are running up against their limits, too. When I spoke to Mary Brandt, a pediatric surgeon at Texas Children's Hospital, she was driving home through receding floodwaters after five straight days of work. She and her colleagues had just completed the first shift of what she described as a “military kind of operation,” and fittingly had just been relieved by a team of reinforcements. “Texas Children's Hospital has leadership that has just gotten this down to an art,” Brandt told me. “Everything was covered.”

That military-like response among Houston-area hospitals was largely effective in dealing with some of the most immediate effects of the storm. Brandt’s team saw mostly children who’d faced non-life-threatening injuries and illnesses. Meanwhile, kids with ailments requiring management, like asthma, or those with fevers and other serious conditions were airlifted to the Texas Children’s Hospital building in The Woodlands, a suburb north of Houston. The triage and logistics systems in place for Houston’s hospitals helped ensure that patients with the most sensitive conditions received treatment and resources on time.

Still, there’s reason to suspect that effective disaster-management system will be stressed in the days to come. As Brandt notes, the bulk of patients with conditions directly related to the floods haven’t yet made it to hospitals. “Since the water's just subsiding,” Brandt said, “we're expecting there's going to be a huge number of patients that are going to come in today and tomorrow with problems that they needed to have taken care of in the last few days, but just couldn't get to us.” That “huge number” might be more than hospitals can handle, as Texas Children’s is already near its bed capacity, and local general hospitals like Ben Taub Memorial have already faced food and drug shortages.

There are a myriad of other health problems to come, and they often affect the most vulnerable citizens. Daring water rescues of Houston residents from nursing homes made headlines, but the most dangerous period during disasters for seniors is actually post-evacuation. According to Gentry: “What we learned through surveys was that even if we had 100 percent of the people evacuated successfully from nursing facilities, within eight weeks they usually saw a 10 percent fatality rate. That 10 percent was due just from the stress that results from the evacuation and the moving.”