British explorer Ranulph Fiennes has pulled out of the expedition to cross Antarctica during the region's winter after developing a severe case of frostbite.

The 68-year-old and his five-member team had hoped to conquer what has been called one of the last great polar challenges — traversing nearly 4,000 kilometers (2,500 miles) in a place where temperatures often dip as low as minus 70 Celsius (minus 94 Fahrenheit).

The expedition, dubbed "The Coldest Journey," said in a statement Monday that the team is working toward evacuating Fiennes from Antarctica, but that the evacuation is being hampered by a blizzard. The rest of the team plans to continue on.

Expedition organizers are trying to raise $10 million for the charity, "Seeing is Believing," which seeks to prevent blindness.