Although it poses no immediate threat to the astronauts in orbit, a malfunctioning cooling pump on the International Space Station required maintenance on Wednesday. A NASA spokesman announced that "one of the station’s two external cooling loops shut down because it was too cool Wednesday afternoon," in maybe the only case ever of something being so damn cool that it was straight-up dangerous. Non-critical equipment was powered down because of the failure.
Engineers at mission control diagnosed the problem as an issue with a valve inside the pump, and shifted power to a second cooling loop. If ground crews are unable to sort the problem out, the astronauts on board might have to plan a spacewalk in order to fix the issue. A similar failure occurred on the ISS without much incident in 2010. According to the admirably casual ISS Twitter feed, the station currently has three spare pump modules.
Loop A NH3 outlet temp reached a minimum of -34.7°C and is now warming up again. Loop B is coping well with the additional loads. #ISS— ISS Updates (@ISS101) December 12, 2013
The situation has not yet been fully resolved, but the six astronauts—two American, three Russian, and one Japanese—are not in immediate danger and "fine for the near future."