Experienced climber Dr Sundeep Dhillon recently joined other participants at The London Clinic near Regent's Park in London to have his vital signs tested ahead of the expedition to Everest Base Camp.
In 1998 and aged just 28, Dr Dhillon became the youngest ever person to complete the Seven Summits challenge, climbing the highest peaks on all seven continents, a record he held for four years.
In March, he will join 200 people taking part in the Xtreme Everest 2 study to investigate the effects of low oyxgen levels on critically ill patients.
Hypoxia is responsible for many deaths in intensive care each year. Researchers hope that better understanding of why some people cope better with low oxygen levels could lead to new treatments in intensive care.
Speaking to GP at the testing day in London last month, Dr Dhillon said: 'What we're told is that [critically ill patients] are hypoxic and therefore sick, so if we give them oxygen they'll get better, and that isn't true and people die quite regularly in intensive care almost regardless of what you do to them.'
A team of doctors including Dr Dhillon had noticed that people responded to hypoxia in different ways at altitude, and that these differences were 'clearly echoed' in critically ill patients.
The idea led to the original study, Xtreme Everest, which made its first trip to Everest Base Camp in 2007.
Xtreme Everest 2 expedition leader Dr Dan Martin, consultant in anaesthesia and critical care medicine at the Royal Free London NHS Foundation Trust, said: 'We're taking well people and exposing them to very low levels of oxygen and looking at the ways in which they respond to them, to pick out mechanisms that are important and ones which may be amenable for us to attempt to alter. Eventually, what we hope to do is to reduce the number of deaths in intensive care.'
His team is still looking for participants with no special training or experience to join the expedition. Dr Martin said: 'They need to move quick, but there are places available.'