New pictures have emerged of the harsh conditions being endured by three British explorers in the Arctic trying to reach the North Pole.
The Catlin Arctic Survey team, led by Pen Hadow, is measuring the thickness of the sea-ice.
The group was down to just one day's food rations, in temperatures as low as -40C with wind chill, before vital supplies arrived by plane.
Ann Daniels explains what it is like to try to cook in a tent in the Arctic.
This is part of a series of reports with Pen Hadow on his latest Arctic expedition.