He who cannot bear discomfort stoically is still a slave to the phenomenal world and its destructive contrasts. The average person constantly reacts to cold, heat and other extremes, thereby increasing the attachment of the soul to the body.
To achieve spiritual freedom, the seeker of spirituality must train his mind to be calm about changes in heat and cold, about suffering and pleasure. In Indian spiritual places, masters teach novices to tolerate any external condition, which allows the mind to become an altar to the immutable spirit.
In response to the influx of conflicting feelings, the average person unnecessarily plunges into anxiety, which is one of nature's most effective weapons of enslaving the mind.
However, don't think that yoga encourages you to catch a cold (and get pneumonia) or get sunburned in the sun. Titiksha (patience and lack of desire) should be developed while taking reasonable measures to eliminate external discomfort.
The practice of Titiksha involves willpower and imagination (active self-hypnosis). Equanimity is achieved through yogic meditation, during which the yogi learns to detach his ego from the sensations received by the soul.
๐ Paramahansa Yogananda