IT'S the middle of the night, and the phone rings. Outside it is thunder and lightning and it is pitch-black. Without thought, the call recipient finds his rucksack, gets into his waterproofs, checks his equipment and heads into the middle of nowhere probably to spend the next five or six hours battling the conditions to save someone's life.

He must be mad, we might think, or at least paid very well - but the members of Clapham's Cave Rescue Organisation - reputed to be the oldest such group in the world - are neither of those things. They are a group of dedicated, highly skilled men and women who give up their own time, unpaid, to help others.

The CRO is based in Clapham and provides a cave and mountain rescue service in the Three Peaks area of the Yorkshire Dales, extending westwards into Lancashire and Cumbria and eastwards as far as Malham and Gordale.

It runs side by side with the Upper Wharfedale Fell Rescue Association (UWFRA), which covers Wharfedale, but the CRO is by no means limited to caving incidents.

Along with mountain rescues, it has been involved in searches and major incidents such as Lockerbie and the search for the schoolgirls who were swept to their deaths in flooded Stainforth Beck.

In addition, the CRO has provided trained personnel and specialist equipment to assist drivers and passengers trapped in snowbound cars, and to help with searches for missing people and murder victims.

Since its formation in 1935, the organisation has assisted approximately 2,800 people aged between five months and 87 years in 1,820 incidents.

Members' expertise is not simply used to help people - numerous dogs, sheep, cows, nine ducks, a cat and a rabbit owe their lives to the CRO.

Currently the organisation has more than 89 members, comprising an operational team of 52 with a further 36 in a support role.

A council runs the organisation and includes the duty and underground controllers, as well as medical, equipment, personnel and training officers. It is elected annually.

Training takes place on the first Wednesday of every month and topics vary from health and safety to problem solving, exercises and learning about new equipment.

On average, the CRO is called out four times a month, and in 2002 it dealt with 45 incidents.

Among the people rescued was an injured caver with the lowest body temperature ever recorded by the CRO.

The man had fallen on the first pitch of Diccan Pot, near Selside, Horton-in-Ribblesdale, in June. He was drifting in and out of consciousness when the CRO arrived. He was brought to the surface and then airlifted to hospital by RAF helicopter.

His core temperature on arriving at Leeds General Infirmary was 24 degrees centigrade and he had serious injuries, fractured ribs, pelvis and spine. He had one and a half litres of blood drained from his chest and part of a lung removed.

The man has said he will never cave again, but his friend told his rescuers: "We are eternally grateful to the CRO - if it wasn't for them my friend would not be alive today!"

On receiving a 999 call from someone in need of the CRO's assistance, the police will contact one of six duty controllers who work on a weekly rota. The duty controller will then alert the operational team members via pager.

Depending on the incident, if more members respond than is needed, they will be asked to stand down. If more members are needed a second call will go out to support members.

Controllers direct the rescue operations, while the operational team comprises experienced cavers, climbers and walkers who train regularly.

On cave rescues, there is a need for operational members both underground and above ground to operate radios and provide support in terms of equipment, food, drink and medical supplies.

On larger or prolonged incidents, they may be joined by members of the police, neighbouring cave and fell rescue organisations, the RAF rescue helicopter and fire and ambulance services.

For some callouts, the organisation uses trained dogs which can cover the countryside far quicker than the members.

Often the team works with limited information - for instance, on one rescue last year, they only had the location "somewhere on Ingleborough".

Also, they may be alerted by relatives waiting for people to return home or passers-by noticing cars still at the foot of hillsides after dark and have no information about what type of rescue they could be embarking upon.

Rescue operations can be lengthy and often members spend hours underground and on the surface in cold and wet conditions.

Sometimes it's a soul-destroying exercise. After a certain length of time, it is inevitable that the individual they have been called to assist will have died.

The professionalism of the members is matched by their sense of humour and it is this, and their team spirit, which help to get them through the difficult or traumatic times.

The Stainforth incident affected many members, particularly those who worked outdoors or had children of their own.

However, members also have fond memories of other rescues.

In October a poodle fell down the open shaft of Sell Gill Holes at Horton-in-Ribblesdale. A CRO member abseiled down to the dog but was told to talk quietly to her as she did not like men.

The animal subsequently spent 24 hours at the vets in Settle, having a broken tooth out and two stitches to her legs. According to the owners. She is now fully recovered, and eager to return to the area in 2003.

But it's not only the people at the sharp end that matter.

Every team member has an important role, and without the fundraisers, there would be no such thing as the CRO, which functions entirely from charity donations.

The biggest fundraiser of the year is the Broughton Game Show, which is held annually with the profits benefiting both the CRO and UWFRA.

The organisation was badly affected in 2001 when the show was cancelled due to the foot and mouth outbreak and the reduced number of tourists meant there were less pennies rattling in their collecting tins.

To keep running, the CRO needs £21,000 to go towards high-tech rescue equipment, the maintenance of its three Land Rovers, the medical equipment and running costs of the team.

It is a frightening thought that but for the willingness of these members to risk life and limb to help others and the efforts of fundraisers, many people would not be here today to thank them.