A massive cleaning is under way at John Jay High School after residents seeking shelter from Sandy's aftermath became sick.

Mayor Michael Bloomberg said during a press conference that about a dozen people who found warmth at the school came down with some sort of stomach virus over the weekend. He says it appears to be minor, but the city isn't taking any chances.

The mayor also announced that mobile medical vans are now stationed in Coney Island, the Rockaways and Staten Island, to help those in need.