Three people in need of medical care were evacuated from McMurdo Station in Antarctica by New Zealand’s air force during a daring 20-hour rescue mission in freezing temperatures and total darkness.

One patient required urgent care, prompting the U.S. National Science Foundation to request help due to limited medical resources.

A Royal New Zealand Air Force C-130J Hercules, equipped with a doctor and night vision goggles, completed the mid-winter evacuation after a U.S. team manually prepared a runway, CBS News has reported.

U.S. officials called the operation “nothing short of heroic.”

Written by B.C. Begley