Tuesday, May 4, 1999 Published at 13:33 GMT 14:33 UK
So you want to climb Everest...
The modern mountaineer - in Mallory's day they wore tweeds
The temperature is dropping, there is mist everywhere, a snowstorm is threatening, and you are a good two hours away from your camp in the Himalayas.
There was a time when if you did not get out of these kind of conditions pretty quickly you could be facing a horrible lonely death.
But climbers now go equipped with a certain degree of confidence that their hi-tech kit means their toes will not drop off just yet and, if caught out, they might just survive to fight another day.
Mallory and Irvine climbed Everest wearing tweed jackets and heavy woolen layers underneath.
Their leather climbing boots were studded with nails, their feet protected by further layers of socks.
Their oxygen system was so primitive and heavy that modern mountaineers question whether its benefits were outweighed by the effort needed to carry it.
Today, the climbing equipment industry is worth millions.
Sir Chris Bonington, Britain's most famous climber and a conqueror of Everest, told BBC News Online: "Between 1924 and 1999 there have been huge developments and changes to equipment which have enabled the climber to be more bold," said Sir Chris.
"Rubber soles came with the war and we saw the development of aluminium which meant that equipment such as tents and rucksacks could be much lighter."
At the same time, the world's first synthetic fibre - Nylon - was being developed - the first of a range of materials that hold less water than natural fibres.
"By 1953 when Edmund Hillary and Tenzing climbed Everest, the oxygen systems were better," said Sir Chris.
"These were based on a system that had been developed by the air force which was that much more sophisticated."
Companies such as WL Gore, Lowe Alpine systems and Berghaus have international reputations based on using materials demanded by the modern sport.
WL Gore describes its flagship fabric Gore-Tex as the standard in waterproof and breathable materials.
Man-made fleece materials are promoted as offering the warmth needed for the worst of conditions - without the weight or water-retaining qualities of wool.
Every aspect of climbing equipment has changed. Tents are so lightweight and compact they can be pitched on the tiniest precipice.
Ropes are manufactured from long-lasting fibres which do not weigh down the climber as they get wet.
One US company has even developed a vest-jacket called the "Avalung", a garment which it says allows an avalanche victim to breathe while buried by sucking the air out of snow.
To top it all, you can now go equipped with perhaps the ultimate gadget - the global positioning system - a device not much larger than a television remote control which tells you almost exactly where you are thanks to satellite communications.
The costs can be huge. A personal top-of-the-range kit will cost upwards of $3,000. A full assault on Everest will not leave much change from $15,000.
Complacency or confidence
Despite the relative accessibility of the sport, mountaineering experts caution against allowing the equipment to create a false sense of security.
Four climbers died on Everest in 1998 - a figure down from 15 in 1996. Thousands of dollars worth of equipment cannot replace years of training and preparation.
"All we are doing with modern equipment and courses is minimising the risks," said Andy McNae of the British Mountaineering Council.
"Mountaineering is a risk activity, you cannot get away from that. There always has to be a judgement.
"It is very easy to be so focused that you ignore things like the conditions and the hour of the day."