After 115 years, the old-school shvitzes at the Russian and Turkish Baths on East 10th Street are getting just a little bit less old. A just-started renovation will add a new, larger sauna and steam bath to the East Village institution, where your bubbe and zayde bathed a century ago — when the Lower East Side tenements often didn't have their own plumbing — and customers today range from Hasidic Jews to celebrities like P. Diddy and Colin Farrell to neighborhood locals, both hipster and non. "We're basically getting rid of an old sauna and putting in a brand-new one," 30-year-old Jack Shapiro, who manages the baths with his brother, told us. They're also adding a new steam room and "prettying up" the stairs to the institution's second level. August, of course, is the time to do this, because sauna business slows down when it's already so hot and muggy outside. But it doesn't stop completely. "After you take a 180-degree steam here," Shapiro explained, "100 degrees outside ain't bad." —Mary Reinholz