As a psychiatrist, Bertrand treated himself with a course of self-hypnosis. And that is the key to surviving such a gruelling trip - having the tools to cope with health problems on board. The balloonists need to be aware of the main risks and be able to deal with any problems that occur. Exhaustion The crew's bodies are put under immense strain over the 21 or so days of a major flight. This means they must get proper rest and avoid stressful situations as much as possible - no easy task given the nature of their challenge.
Exhaustion can severely impair performance, and is caused by insomnia, illness, stress and overwork.
He did some self-hypnosis, as he is a psychiatrist, and had a couple of soups and some oxygen and he got a new lease of life. Self-hypnosis can be used relax the mind in times of extreme stress. This is said to leave the mind open to therapeutic suggestions and strengthen will-power. Should the cabin's heating systems fail, the balloonists will face two main threats - hypothermia and frostbite. Hypothermia symptoms take effect in stages, starting with bouts of shivering and an inability to think straight.