Tapah refers to austerities. We must voluntarily accept inconvenience or physical austerity for a higher purpose. Sometimes we think that austerities mean we have to put ourselves into a suffering condition, but Srila Prabhupada explained in a lecture in 1976 that one need not place himself in a circle of fire in the middle of the summer, or submerge himself in cold water in the middle of winter, in order to perform some austerities. Rather, our austerity is to strictly follow our spiritual master’s instructions. The results of all other austerities are then automatically achieved. The purpose of all austerity is to reduce the bodily conception of life, which is the cause of material bondage. It is extremely difficult to overcome ahankara, false ego. Because of false ego we identify ourselves with the body, its extensions, and to everything we feel we require to satisfy the body’s needs. Of course, when we satisfy the Lord by our austerities, we feel spiritually satisfied and automatically our bodily conception of life decreases.
(LFD, Vol2, Faith—The Price for the Holy Name, Pg 90, 3rd paragraph)