Cool temperatures call for balmy picks. BUY Castle Starr Sample Sale What: Cult-hit label delivers dresses, tops, and pants at 40-60 percent off. Why: You, too, will look like a celestial body. When: Thurs., 11 a.m.-8 p.m.; Fri., noon-3 p.m. Where: 215 W. 40th St., b/t Seventh & Eighth Aves., 11th flr. Opening Ceremony Overstock Sale What: It’s USA vs. UK. Save 75-90 percent on Alexandre Herchcovitch, Cloak, Patrik Ervell, Hussein Chalayan, and more. Why: Any clothes-ing remarks? When: Fri. & Sat., 11 a.m.-8 p.m.; Sun., noon-7 p.m. Where: 35 Howard St., b/t Broadway & Crosby Sts., 5th Fl. (212-219-2688). Cash only. DO Herbal Thai Poultice Massage What: Centered on the healing traditions of Thailand, the three-step treatment targets pressure points to fix what ails you. Why: You’re hooked on a feeling. When: By appointment. Where: Haven, 150 Mercer St., b/t Prince & Houston Sts. (212-343-3515). Annual No Pants Subway Ride What: Wear normal winter clothes, swipe your MetroCard, ride the 6 train, then take ’em off. Why: You’ve seen London. You’ve seen France. When: Sat., 3 p.m. sharp! Where: Meet near the black sculpture at Foley Sq., b/t Centre & Lafayette Sts. Click here for a map. HEAR O’Death What: Join the vagabonds in howling along to haunting country melodies. Why: It’s a new folk tradition (complete with whiskey and feverish banjo). When: Sat. at 11:30 p.m. Where: Sin-é, 150 Attorney St., b/t Stanton & Houston Sts. (212-388-0077).