Yoga Sutra 2.48 he becomes immune to the opposites
Sūtra II.48
From that, he becomes immune to the opposites
When a posture has been mastered, he is not overwhelmed by opposites like heat and cold.
From that, he becomes immune to the opposites. From that, from becoming firm in a posture. He gives an example of what he means: not overwhelmed by opposites like heat and cold.