A freaky flash fire in a mechanical room of a building on the Columbia-Presbyterian Hospital campus left a maintenance worker with burns over 70 percent of his body this morning. A little before 10 a.m. workers were cleaning a domestic hot water tank in a 22nd-floor room, when, suddenly, there was "a little bit of an explosion and a flash fire," according to an FDNY spokesman. City Room reports that vapors from the cleaning solution were ignited after someone turned on a halogen lamp inside the drained tank. Accidents are not uncommon with halogen bulbs, which can reach temperatures as high as 1000 degrees and easily ignite any combustible material nearby. While they are more energy-efficient than incandescent bulbs, some have called for them to be banned; two years ago a rash of fires in Australia prompted one firefighter to call halogens "a bloody nightmare." All three workers injured in today's blaze were rushed to Harlem Hospital. One worker injured his arms and hands when he tried to pull the first man out of the tank, and the third suffered respiratory injuries.