1) HALACHAH: WEARING A WIDE-BRIMMED HAT ON SHABBOS

OPINIONS: The Gemara discusses the conditions under which one may wear a "Siyana" on Shabbos. What is a Siyana, and under what conditions may one wear it on Shabbos?

(a) RASHI explains that a Siyana is a wide-brimmed hat. If it is not worn tightly (Mehudak) on the head, there is a concern that the wind might blow it off and one will pick it up and carry it in Reshus ha'Rabim. (According to Rashi, "Mehudak" means "tight" and is the condition that permits a wide-brimmed hat to be worn on Shabbos.)

(b) TOSFOS cites RABEINU CHANANEL who says that a Siyana is a hat or head covering. If the brim is made from a hard material that does not bend, the hat may not be worn on Shabbos, because it is considered an Ohel. When the brim is soft and pliable, the hat may be worn on Shabbos. (According to Rabeinu Chananel, "Mehudak" means that it "does not bend" and is the condition that prohibits wearing a hat on Shabbos.)

(c) The RAMBAM writes that a Siyana refers to any Talis or overgarment which a person drapes over his head and which protrudes in front of him or to the sides. If it is tightly bound to his head and it is stiff and does not bend, it is like an Ohel and may not be worn. (Apparently, according to the Rambam, "Mehudak" means both that it is "tight" and that it "does not bend," and it is the condition that prohibits wearing a hat. See TESHUVOS RADVAZ in Leshonos ha'Rambam.)

HALACHAH: Is one permitted to go outside with a hat with a wide, stiff brim on Shabbos? According to Rabeinu Chananel, to wear such a hat should be prohibited, because it is like an Ohel. According to Rashi, it should be prohibited only if it is not worn tightly on one's head.

The MISHNAH BERURAH (OC 301:152) lists a number of reasons to permit one to wear a hat on Shabbos:

First, the MAGEN AVRAHAM rules that if the brim of a hat is sloped downward, it is not considered an Ohel and may be worn.

Second, one may rely on Rashi's opinion that it is prohibited only when it is worn loosely.

Third, the hats commonly worn today are not worn in order to provide shade, and thus they do not serve the purpose of an Ohel.

Finally, if the brim is not stiff, the hat certainly is permitted.