Flames were first reported just after 6 a.m. Wednesday on the 5300 block of Spruce Street.
When firefighters arrived, heavy fire and smoke was showing inside both homes in the twin. Fire was also spreading across the front porch area.
A 50-year-old man was removed from the house. He was taken to The Hospital of the University of Pennsylvania having suffered third degree burns over 50-percent of his body. He is listed in stable condition.
A teenage boy was also hospitalized having suffered burns to his arm.
The fire was placed under control at 6:24 a.m.
There is no word on what sparked the blaze.