"When You Work Under the Sun, You Need to Stay Hydrated" (炎天下の作業には水分補給が必須ですのよ Entenka no Sagyō ni wa Suibun Hokyū ga Hissu desu no yo?) is the second episode of the Toaru Kagaku no Railgun anime series. It was first brodcasted on October 9, 2009.