Summit season is about to start at Everest Basecamp, and the doctors working at the highest hospital in the world gear up to deal with a constant stream of life-threatening emergencies. With hundreds of climbers about to enter the death zone, it is only a matter of time before Everest claims its first casualties.

At the foot of Mount Everest, a climber comes into the basecamp clinic at death's door. Can the doctors save his life and fly him out? As the Everest summit season gets underway, climbers are exposed to a lethal range of high-altitude illnesses, trauma and frostbite, and the world's highest clinic gets busier and busier.

At Everest Base Camp, a UK scout pays a painful price for reaching the top, and three climbers set off for a record-breaking second summit in seven days. With base camp melting and the monsoon approaching, is there still time to risk a final push to the top?