Bringing a Baby into a Pool on Shabbat and Yom Tov
Question
Answer
Hello
1. The custom among Ashkenazim is not to bathe on Shabbat and Yom Tov even in cold water due to several concerns, primarily the squeezing of hair. Except in cases of distress or great need.
2. In cases of great need, such as a very hot day when the baby is suffering, it is permitted to bathe him in the pool, but care must be taken to avoid squeezing. Therefore, the swimsuit should not be removed in a way that will certainly squeeze out water.
3. There is no difference regarding squeezing between Shabbat and Yom Tov.
Source
Mishna Berura, Siman 326, S"K 21
The poskim wrote that it is customary not to bathe at all in a river or mikvah as it is likely to lead to squeezing hair and for several other reasons, see MA etc. However, hands and feet may be washed in a river if dried before walking 4 amot [AR]: