Drying one’s body after Mikveh or a cold shower on Shabbos:
One who immerses in a Mikveh on Shabbos, or takes a cold shower in mitigating circumstances [i.e. heat duress; remove sweat or dirt], must be careful to avoid transgressing prohibitions involved in the drying process of the water that is on his body. In general, there are three Halachic aspects involved in drying the body that one must be aware of:
- The requirement to dry the water off the body before entering an area without an Eiruv.
- The requirement to avoid the squeezing and laundering prohibition with the clothe that one uses to dry himself.
- The requirement to avoid squeezing water from the hair and avoid drying it in a way that causes the water to squeeze.
The need to dry:
It is forbidden for one who washes his body [i.e. shower, or Mikveh, or even washes his hands] to carry the water that is on his body in an area without an Eiruv. [Thus, if there is no Eiruv one’s city, one must dry the drops of water from his body/hands prior to exiting the home or building. If one immersed in a river or ocean, he should not walk at all with the water on him, even less than four cubits. Thus one is to prepare a towel, or place his clothing, near the shoreline and dry himself there prior to walking.]
May one walk into a public domain after Mikveh a shower if there are still drops of water in one’s hair or beard?
Issue of getting the towel or clothing wet:
It is permitted to dry oneself with a cloth on Shabbos. This applies towards any cloth, even if one is particular during the week not get the clothing wet, [such as a shirt and the like]. Nevertheless, it is best to use an item which one is not particular to squeeze [such as a towel] to do so rather than using clothing which one is particular to squeeze out their water upon them getting wet. Likewise, it is best to shake the water off one’s body prior to drying himself, even though from the letter of the law there is no need to do so, and the custom is to be lenient. [This applies even when using a towel designated for drying.]
Should one dry himself with a towel on Shabbos rather than wear his clothing while still wet?
Yes. It is better to use a towel, as one’s clothing is not designated for drying with and he may therefore come to squeeze the water from it.
 See Admur 326:1 regarding the allowance to bathe in cold water on Shabbos and 326:6 regarding the custom to nevertheless avoid bathing in cold water and Admur 326:7 regarding the allowance to immerse in a Mikveh and Ketzos Hashulchan 133 footnote 8 that this applies even according to the custom and that it is permitted to shower if one is bothered by the heat. So also rules: Igros Moshe 4:74; Beir Moshe 6:73; Dvar Yehoshua 2:54; Az Nidbaru 1:61; SSH”K 14:1; Piskeiy Teshuvos 326:8; Shabbos Kehalacha 18:40; [Minchas Yitzchak 6:32 implies that one may not bathe in cold water even to cool off, and may only do so for the sake of a Mitzvah, such as to use a Mikveh, however he then concludes by bringing the Ketzos Hashulchan ibid which is lenient.]
 Admur 301:61 “It is permitted to stand on the bed of the river and wash one’s hands in its water. There is no prohibition involved in the removal of the water which is on his hands from the river onto the bed being that the river is a Karmalis and the bed of the river is likewise a Karmalis and it is permitted to remove [items] from one Karmalis to another Karmalis within the distance of four handbreadths. However one must beware to dry his hands well immediately after removing them from the river prior to walking four cubits.”; 326:6 “One who bathes in a river [on Shabbos] needs to dry his body well when he comes up from the river so that no water remain on him and have him carry it 4 cubits in a karmelis as explained in chapter 301 [Halacha 61].”; Michaber 301:49; 326:7; Rav Yehuda 141a; Tashbatz 34; Rabbeinu Yerucham 17
 M”B 326:22; However see Admur 301:61 and 326:6 who implies that it is permitted to be done, so long as he does not carry it four Amos
The reason: Although we rule [in 349:1] that one may carry within his four Amos, nonetheless here we suspect that one may come to carry the water that is on him even more than four Amos, and hence we require him to dry himself right away. [M”B ibid]
 M”B 326:22
 P”M 326 M”Z 2; Teshuvos Vehanhagos 2:178; 4:90; Eretz Tzevi 1:73; Har Tzevi 1:197; Kinyan Torah 4:32; Bris Olam Rechitza 18; Az Nidbaru 2:43; Divrei Moshe 1:16; Beir Moshe, Divrei Malkiel, Piskeiy Teshuvos 301:22 [66 in new]
Other opinions: Some were careful to dry the beard prior to walking 4 cubits [or leaving the Mikveh to a public domain which does not have an Eiruv]. [Steipler brought in Teshuvos Vehanhagos ibid; Piskeiy Teshuvos ibid footnote 465]
 The reason: It is allowed being the water does not contain Shiur Hotzaah, and is likewise not the common way of carrying and hence the Sages did not decree against it even in a Reshus Harabaim. [P”M ibid] Likewise, the drops of water being that the drops are nullified to one’s beard, as is the law regarding water absorbed in a cloth.
 Admur 301:60 “One who washes his face hands and feet in hot water which was heated from before Shabbos, or even [one] who bathes his entire body in the Tiberius springs, or in cold water, the [Sages] permitted him to dry himself with a towel or sheet and the like, even if one is particular during the week to squeeze these clothes from their absorbed liquid. Nevertheless, it is best to dry oneself with an item which one is not particular to squeeze even during the week.”; Michaber 301:48; Shabbos 147b
The reason it does not contain a Biblical laundering prohibition? As it is Derech Lichluch and not Derech Kibbus. It is therefore permitted to dry oneself with a garment after bathing even if he has a lot of water on his body. [Admur 302:21; Rama 302:10]
The reason that this does not involve a Rabbinical laundering prohibition: The Sages did not suspect that one may forget and come to squeeze the towel on Shabbos being that this decree would be a decree which is impossible to implement, as being that all bathers need to dry themselves, if they were to prohibit drying in essence they would be prohibiting people to bathe, which is a matter that is impossible to prevent people from doing. [This inability to withstand the decree is known from past experience as] one time the Sages decreed not to bathe [even in water heated by fire before Shabbos] due to the bath house attendees which would heat up the water on Shabbos while claiming that it was heated before Shabbos, and afterwards [they decreed against even bathing in the Tiberius springs being that people would bathe in fire heated water claiming that it was Tiberius spring water, and afterwards] the Sages saw that the public is unable to uphold the decree and they thus retracted and rescinded it. Now, although today in which it is possible to abstain from bathing on Shabbos [and thus the decree is now one which can be kept by the public], and thus it is possible to decree against drying oneself, nevertheless drying oneself contains no prohibition being that it was never prohibited by the council of Sages [which are the only authority to make such decrees]. [Admur ibid; M”A 301:58]
 Admur ibid; Implication of M”A 301:58; however see M”A 302:22
 M”B 301:173 in name of Gr”a
 Admur ibid; M”A 301:58; However regarding drying hands on a cloth, the M”A 302:22 rules it is forbidden to use a garment that one is particular not to get wet. However, see M”B 302:51 in name of Peri Megadim that argues one may be lenient by a small amount of water.
 Admur 302:21; Michaber 302:10; See Rama there; Piskeiy Teshuvos 302:24; Shabbos Kehalacha 18:56
The reason: As there are opinions [Yireim; Maharam; Mordechai] who rule there is a laundering prohibition involved in wetting a clothing even in a form of drying and only when a small amount of water is used is it allowed. [See Admur ibid and Kuntrus Achron 302:1; M”B 302:50]
 Shabbos Kehalacha 18:55-56; Piskeiy Teshuvos 302:24