How should one mix hot water and cold in order to wash one’s hands or face?

We learned in the previous shiur that one may wash limited areas of one’s body with hot water on Shabbos provided that a) one does not wash the majority of one’s body and b) that the water was heated before Shabbos. One of the methods is to take hot water from an electric Shabbos urn or to use some water from the kettle that is on the Shabbos hot plate or blech. This water is heated before Shabbos and may therefore be used for this purpose.

The problem is that this water is too hot to bathe with, and for practical reasons it must be mixed with cold water. Mixing hot and cold water can result in the ‘cooking’ of the cold water and therefore must be mixed in a permitted manner.

Two methods are feasible and permitted:

1)                   Pour hot water from the urn etc. into a dry vessel and add cold water to cool it. Since the vessel the hot water is now in is called a k’li sheini, one may add ‘uncooked’ water to a k’li sheini and it does not ‘cook’ in that k’li. [1]

2)                   Pour hot water from the urn etc. onto cold water making sure that only a small amount of hot water is poured thus ensuring that the mixture does not reach the temperature of yad soledes bo. [2]

If a gentile heated water on Shabbos for an ill person, may someone else wash with that water?

The Shulchan Aruch [3] teaches us that if a gentile cooked for a sick person on Shabbos, a healthy person may not partake of that food on Shabbos. [4] The reason is because Chazal were afraid that the gentile would purposely add food to the pot for the healthy person. [5]

The same reasoning is applied to our case. Were it permitted for a healthy person to bathe in the hot water heated for a sick person there is fear that the gentile would heat water specifically for the healthy person. Accordingly a healthy person may not wash with that water.

Is one permitted to take a cold shower on Shabbos?

The abovementioned problems pertaining to hot water do not apply to bathing in cold water. However there are other problems. The Shulchan Aruch [6] teaches us that when one washes in a river on Shabbos, when coming out of the river one must take care to dry himself before walking four amos, because he will be ‘carrying’ the water in a carmelis. [7]

The Mishna Berura, quoting the poskim, says [8] that the custom is not to bathe in a river on Shabbos at all because of the various pitfalls involved with such bathing.

Just to mention two: carrying the water more than four amos on the river banks and drying hair, which is a problem of squeezing. [9]

Many poskim are of the opinion that there is no difference between taking a cold shower and bathing in the river. Accordingly one must refrain from taking a cold shower or bath on Shabbos. [10]

HaRav Moshe Feinstein ztz”l writes [11] that although one ideally could make a distinction between a shower and bathing in the river, nevertheless one should not take a cold shower on Shabbos.

Does that mean that there is no heter whatsoever to take a cold shower even when necessary?

Rav Moshe writes that when necessary, such as during a heat wave etc. and one feels that a shower is of paramount importance, one may take a cold shower. [12] One should refer to a rav for guidance.

How is one to dry oneself after a cold shower?

The main problem is squeezing water from wet hair. This is an issur d’rabanan [13] and therefore when drying a beard or drying hair on Shabbos, care must be taken not to squeeze water from the hair.

However, Rav Shlomo Zalman Auerbach writes [14] that when squeezed directly into a towel, it is permitted, i.e. by placing the towel over one’s hair or beard and gently rubbing the hair into the towel, thus ensuring that the water is not squeezed onto the floor.

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[1] Simon 318:13. See also the SS”K 1:53.

[2] See the SS”K 1:51 based on the Bi’ur Halacha in simon 318:12. Yad soledes bo: 40º-45ºC or 104º - 113ºF.

[3] Simon 318:2.

[4] Disregarding the issue of bishul akum - food cooked by a gentile.

[5] See the M”B 318:13 whether and when it is an issur d’oraisso or only a d’rabanan.

[6] Simon 326:7, and see M”B 22.

[7] A reshus harabim d’rabanan.

[8] Simon 326:21.

[9] Either under the umbrella of Libun or Dash.

[10] See the SS”K 14:11. The ???? ????? in the name of the Chazon Ish, the ???? ???? and others.

[11] Igross Moshe Orach Chaim vol. IV simon 74 page 145 and simon 75.

[12] See the SS”K 14:11.

[13] M”B 326:25.

[14] SS”K 14 footnote 64.