Han helped establish the Rebel Alliance new base on the ice planet Hoth. After Luke didn’t return from a routine sweep of the planet surface, Han headed out alone into the frigid cold to find him. He finally located the young Jedi, but Luke had suffered severe injuries[..]. The two were found by the Alliance the next morning, and Luke survived. But old problems lingered; Han was still wanted by Jabba the Hutt and had to pay off his debt. While preparing to leave [..] the Empire attacked the base, and Han changed his plans, evacuating Leia on the Millennium Falcon.
from – Han Solo | StarWars.com