Firefighters responded to the 2-alarm fire in south Bethlehem around 2 a.m. Tuesday.
Deputy Fire Commissioner Robert Novatnack said the blaze appears to have started in the first-floor bedroom belonging to Lehigh student Andrew Douglas.
He said Douglas suffered burns on various parts of his body and is being treated at a burn unit for non-life-threatening injuries.
Fire Capt. Raymond Buttillo said one firefighter suffered a back strain but didn't require treatment.
A total of 15 residents in the area were forced from their homes because of the fire.