Rashi on Ezekiel
they shall not gird themselves in a place that sweats We learned in a baraitha (Zeb. 18b, 19a): They do not gird themselves in a place where they sweat, neither above their elbows nor below their loins, which is a place of sweat, en la suor in O.F., on (whatever causes) sweat. Another explanation: The Torah prohibited the priests from wearing woolen raiment because wool causes the body to sweat (not found in some editions).