The Sefer HaChinuch #564 writes that it’s forbidden for a woman to wear men’s clothing.
If it’s cold outside, is a woman allowed to wear a man’s coat to keep warm?
If #1 is a problem, are any distinctions made that would allow a woman to wear her husband’s coat while her husband is with her?
From Rav Aviner's tshuvot (text)
Wearing Wife's Jacket in the Cold
Q: Is it permissible for a husband to wear his wife's jacket if he is cold, or is it forbidden on account of "Lo Yilbash" (the prohibition of cross-dressing)? And what about visa-versa?
A: It is permissible, since the purpose is not to wear it but simply to warm up (Shut Yabia Omer 6:14).
The prohibition comes from Devarim 22:5, for which Rashi provides commentary as follows. Please click on the image to view "full screen" mode.
Rashi is citing from the relevant section of the Babylonian Talmud (b. Nazir 8:1a, II.4.E [Folio 59A]), which appears as follows. Please click on the image to view "full screen" mode.
The yellow highlighted area indicates that the intent is the issue in addition to the concomitant public perception. Is there apparent intent for the woman to dress like a man, or a man like a woman?
This citation from the Talmud is also interesting because the stipulation includes that women cannot be soldiers (please note last paragraph where Jacob Neuser mistranslated the word "wore," which should be "war").
REFERENCE:
Neusner, Jacob (2011). The Babylonian Talmud: A Translation and Commentary. Peabody, MA: Hendrickson Publishers, pp. 222-223.
Igros Moshe (OC IV, 75 s.k. 3) says that the halacha follows the taz, and it is indeed permitted to wear a man's garment to protect from the cold.
However, the Chochmas Adam, who is widely considered the authoritative decisor in aspects of Yoreh Deah, states (CA 90, 3, and nishmas adam there) that there are two distinct prohibitions.
If a woman wants to wear a man's garment, it is forbidden, regardless of why she wants to wear it.
If she wants to perform an action which only men do, she is permitted to do so if she has a good reason, since she does not intend to use it to look nice or to imitate a man. Therefore, she is permitted to use a man's walking stick so she won't fall, but not if she wants it to look nice. A man is permitted to shave hair which women usually shave, if he does so to avoid skin irritation in that area.
This hinges on how to understand the prohibition on a woman to wear weaponry (gemara nazir 59); see their logic in the sources cited.
