Other poskim disagree since, in their opinion, a plastic cover is not an extension of the hat, but rather a separate object that protects the hat. Since it protects the hat itself rather than the person wearing the hat, it is not considered derech malbush and may not be worn.
However, all poskim agree that it is permitted to wear the plastic cover if it will protect the person from the rain. Similarly, a woman may wear a rain bonnet over her sheitel, since the bonnet protects her head as well as the sheitel.
But regarding an item which is not designed to fit the hat, such as a standard plastic bag or a shawl, all poskim agree that it may not be worn to protect a hat. However, if the bag or shawl is placed over the hat in such a way that it protects the face, neck, or body, then it is permitted.
It is permitted to wear a raincoat even if the main purpose of the raincoat is to protect the jacket or suit underneath the coat.
The same holds true for wearing galoshes to protect one’s shoes from rain or snow.
Sources:
- Yitzchak 3:36; Shemiras Shabbos Kehilchasah 18:45; Teshuvos V’hanhagos 1:240; Rav C. Kanievsky (Shabbos L’Yisrael, pg. 478); Megilas Sefer 41:12.
- Rav M. Feinstein (quoted in Rivevos Efrayim 6:200). [All authorities agree that labels that are sewn into a garment and are meant to remain there permanently, such as labels bearing a company name, laundry instruction labels, and sha’atnez-free tags, are considered an extension of the garment and need not be removed.]
- Rav M. Feinstein (oral ruling, quoted in The Shabbos Home, pg. 121; Mesores Moshe, vol. 1, pg. 119); Vaya’an Dovid 4:43.
- Har Tzvi (Tal Ha’rim, pg. 296); Chelkas Yaakov 99; Rav S. Z. Auerbach (quoted in Shemiras Shabbos Kehilchasah 18:10); Yabia Omer 5:24; Shevet Halevi 1:61-3.
- Chazon Ish (Dinim V’hanhagos 15:13); Igros Moshe 1:108-110; Minchas Yitzchak 3:26-8; Ashrei Ha’ish 14:11; Chut Shani 88:13. [The hood for covering the hat that is part of the “Me’il” or “Shayne Coat” is not included in this prohibition and may be worn.]
- Aruch Hashulchan 301:66; Shemiras Shabbos Kehilchasah 18:10 and footnote 46.
- O.C. 301:14.
- Minchas Shabbos 84:18; Igros Moshe 1:108-109.
