Lin Jin rested for about half an hour before the chills in his body dissipated. However, being skilled in Vein Strengthening, Lin Jin realized that this cold had miraculous effects on him practicing this cultivation method. He tried it out and sure enough, it worked. This was considered a blessing in disguise. By using a fire-spirit imbued needle to regulate his veins with the cold in his body, the effective rate of Vein Strengthening increased.
This was the reason why Lin Jin invested so much time and effort into Vein Strengthening. At least his physical body and spirit energy would grow stronger.
After he recovered enough energy, Lin Jin treated the white ape in case that old dragon came back for trouble. However, he was also sure that the old dragon didn't gain anything from this incident. That last attack Lin Jin performed by messing up one of his veins was enough to keep the old dragon away for a period of time.
In addition, he might be scared too.