The gopis‘ minds are always engaged in relishing the sweetness of Krsna’s body. He is the ocean of beauty, and the luster of His body and the beauty
of His face and smile are all-attractive to the minds of the gopis. In the Krsna-karnamrta, Krsna’s body, face and smile have been described as sweet, sweeter and sweetest. When there are three kinds of contamination in the bodily constitution, convulsions take place. Similarly, a perfect devotee of Krsna experiences convulsions when he is overwhelmed by seeing the beauty of Krsna’s body, face and smile. Before Krsna’s beauty, the devotee sometimes stays immersed in this ocean of transcendental convulsions without receiving treatment, just as a patient suffering ordinary convulsions may be prevented by a physician from receiving a drink of water for relief.

From Teachings of Lord Caitanya, Chapter 10: The Beauty of Krsna by Srila Prabhupada