What about taking a cold shower during heat spells?

The previous shiur stated the reasons not to bathe in hot water on Shabbos. None of the reasons are applicable to cold showers or bath   s, and yet people refrain from that as well. What is the reason for this?

It is customary to refrain from cold showers and baths and the Magen Avraham [1] lists several reasons for this.

• Squeezing wet hair. Squeezing water from wet hair is rabbinically forbidden and were it permitted to take a cold shower one might squeeze wet hair.
• Carrying water. It was normal to bathe in rivers, and emerging from a river with water on one’s body and walking four amos in a carmelis involves a rabbinical prohibition.
• Floating. It is rabbinically prohibited to swim on Shabbos lest one fashions a raft. [2]

Do these reasons mentioned apply nowadays?

Firstly, all reasons mentioned in Chazal almost always apply; and if not in one location then in another. For example, one would not necessarily jump into a river on Shabbos in the city, but when vacationing in the mountains during a hot summer, one might.

Secondly, squeezing wet hair certainly applies and is the main reason nowadays.

And during a heat spell?

Many poskim [3] are of the opinion that there is no difference between a bathtub, mikveh and shower even as far as washing in cold water is concerned. Rav Moshe Feinstein ztz”l writes [4] that one should refrain from taking a cold shower unnecessarily even though it is not brought down in the earlier seforim to prohibit a shower.

And yet Rav Moshe writes that when suffering from heat one may take a cold shower. [5]

But the problem of squeezing wet hair remains?

Indeed it does and great caution is needed not to violate an issur d’rabanan.

Rav Shlomo Zalman Auerbach ztz”l writes [6] that squeezing water from hair directly into a towel is permitted, just as we find that one may squeeze a lemon onto fish; in both cases a liquid is not produced. The way to do it is to place a towel on one’s hair and slowly and gently rub the towel on the hair. Rubbing hard or quickly can cause water to drip from the hair onto the floor etc. which is prohibited.

Rav Sternbuch shlita pointed out that custom is nevertheless to be stringent because it is hard to make sure that water not drip onto the floor.

What other issues are related to showering on Shabbos?

Sponges or cloths are prohibited on account of squeezing. [7] This applies to washing hands and face as well, which is always permitted, albeit not with water heated on Shabbos.

Soap is forbidden to use. Several prohibitions are associated with using soap on Shabbos although not all reasons are always applicable.

• Molid – creating. The Rama explains [8] that transforming the solid soap into liquid is molid similar to transforming ice into water.
• Memare’ach – smoothing. [9] The soap might have rough edges and rubbing it between one’s palms smooths it back into shape.

What about using liquid soap?

It is customary to use liquid soap on Shabbos because both problems mentioned do not exist. However, Rav Moshe Feinstein ztz”l is stringent even with liquid soap, [10] because the bubbles produced demonstrate that the soap can be spread even thinner than it is, which involves memare’ach. Consequently, many dilute liquid soap before Shabbos in order to use it on Shabbos.

May one warm wet hands next to a heater on Shabbos?

Seemingly, if one is careful that the water on one’s hands does not cook i.e. it does not attain the temperature of yad soledes bo [11] it is permitted. It is not so.

The Rosh (perek 3:9) learns that warming water on one’s body next to a fire is equivalent to bathing in hot water that was heated on Shabbos and therefore he writes that one may not even warm one’s hands next to a fire subsequent to washing. (This is how the M”A explains the Rosh).

One should first dry one’s hands and then stand next to a heater. [12]