HOUSTON—Hospitals across the South grappled with water shortages Sunday in the wake of a devastating winter storm as the region carried on with recovery efforts and the weather offered a balmy respite—temperatures as high as the mid-60s. At the height of last week’s storm, hospitals scrambled to care for patients amid record cold temperatures, snow and ice that battered parts of the country more accustomed to going through winter with light jackets and short sleeves. The icy blast ruptured water mains, knocked out power to millions of utility customers and contributed to at least 76 deaths—half of which occurred in Texas. At least seven people died in Tennessee and four in Portland, Oregon. A rural hospital in Anahuac, Texas, about 50 miles (80 kilometers) east of Houston, lost both water and power. William Kiefer, CEO of Chambers Health, which runs the hospital along with two clinics and a wellness center, …