Leaping out of a window with "flames roaring right behind me," Pony made it out of the burning church after helping Johnny pull out several of the children inside. But he soon passed out after Dally "clubbed me across the back as hard as he could." Pony's back was on fire, but his heavy jacket protected him from any severe burns. He awoke in the ambulance, suffering from smoke inhalation and shock. Pony was later treated for "a few burns and a big bruise across my back," and he fell asleep in the car ride home; Darry carried him inside. But Pony was far from healthy. He had a nightmare that first night, and later the next day he had a headache, so he took five aspirins just before the rumble. After the fight--and the deaths of Johnny and Dally--Pony awoke in a daze, suffering from a fever as well as "exhaustion, shock, (and a) minor concussion."
He wasn't in bad condition maybe a little burnt in some places, but what saved him is the jacket Dally gave him. If the jacket was on he probably would have been as bad as Johnny. Also from that Dallas also saved him by putting out the huge fire on Pony's back with his hands.
He was not severly injured. He just got a bruise on his back and some slight burns because Dally's jacket saved him