On Yom Kippur the Kohen Gadol got cold feet TB Sanhedrin 18

With daf TB Sanhedrin 18 we begin the second chapter of our massekhet. The first Mishna teaches that the High Priest, Kohen Gadol, is not exempt from judge duty nor litigation. “The High Priest judges others if he is sufficiently wise, and others judge him when he transgresses. He testifies before the court and others testify concerning him.” (Sefaria.org translation) Nevertheless, the Gemara provides one exemption. The Kohen Gadol may not participate in the court that decides to inter-calculate an extra month into the calendar. “A High Priest does not serve as a judge concerning this matter due to the cold.” (Sefaria.org translation)

Rashi and Tosefot disagree how to interpret “due to the cold.” Rashi explains that the High Priest had to immerse himself into a mikvah five times on Yom Kippur. The water in the mikvah would be freezing and uninviting. Tosefot doesn’t understand Rashi’s explanation because the mikvah water would be heated. They explained that the Temple’s floor was marble. Walking upon it with bare feet would be quite uncomfortable. Either way if a month is added to the calendar and the High Priest must perform his Yom Kippur immersions deeper into the cold autumn, he too will have a vested interest in not adding a month. Consequently, he is exempted from this judge duty.