Van Horn, Texas, Border Patrol authorities last week discovered nearly three dozen migrants crammed inside a U-Haul truck amid a sweltering heat wave that has roiled much of the western United States.

On June 10, Big Bend Sector law enforcement recovered a total of 33 people, of whom 12 were transported to local hospitals in a possible human smuggling operation, officials announced on Tuesday. Agents said the migrants “were close to perishing due to excessive heat and lack of fresh air in temperatures still hovering near 100 degrees.”