Image source: ESA, NASA
Italian astronaut Luca Parmitano experienced a life-threatening accident during a spacewalk in 2013. There was a water leak in his helmet which nearly cost him his life.
On July 16, 2013, Parmitano stepped outside the International Space Station (ISS) to perform a spacewalk that was supposed to last for 6.5 hours. He was joined by NASA astronaut Chris Cassidy and both were carrying out routine tasks outside the ISS. Approximately 45 minutes into the spacewalk, water began to accumulate inside Parmitano's helmet.
Parmitano told Mission Control about the water but he didn’t think it was a problem and Mission Control assumed that the water was coming from a leak in his In-Suit Drink Bag, which is inside the helmet. However, the situation worsened as the astronaut said that the amount of water increased and moved from the back of his head to his face and into his eyes, nose, and mouth.
The spacewalk was terminated and Parmitano and Cassidy were told to return to the airlock. But both were on the opposite sides of the ISS. What made matters worse was the Sun had just gone behind the Earth and it was dark. Parmitano couldn't see but managed to reach the airlock with great difficulty. Finally, his helmet was removed and the ISS crew wiped about 1/3 gallon of water from his head and helmet.