The "Tardis-like" Sea King rescue helicopter has the capacity for 17 casualties
Rescue services are being stretched to the limit as winter's icy bite still grips the UK.
In some parts helicopter crews from military search and rescue teams have had to step in, responding to a record number of call-outs as the snow and ice makes it almost impossible to reach casualties and those in need of help.
The BBC's Wyre Davies spent the weekend with search and rescue teams based at RAF Valley on Anglesey, Wales.
At this time of year, on a cloudless day, Snowdonia is a climber's paradise.
The summit of this Welsh mountain is covered in snow and there are several classic winter climbing routes in the immediate area.
What is different now is that the exceptionally high levels of snowfall and prolonged sub-zero temperatures make Snowdonia seem more like the higher reaches of the Alps.
The weather has also meant an extraordinarily busy period for the pilots and aircrew of 22 Squadron, "C" Flight, at RAF Valley.
They are a jovial bunch. In true RAF style, almost everyone is known by their nickname; "Spike", "Bart", "Sticky", etc.
Occasionally, one appears to have slipped through the net and has managed to 'keep' his given name - but that seems to be the exception rather than the rule.
Nicknames aside, the crews, who work exhausting 24-hour shifts, are absolutely serious and committed to their jobs.
With the new year less than two weeks old, the search and rescue helicopters based around the UK have been called out 100 times already.
For pilots like Captain "Sticky" Bunn, that means perilous flying sorties above the narrow valleys and sharp peaks of Snowdonia, rescuing fallen or injured climbers.
The risk of icing on the helicopter's blades, vicious down-drafts and poor visibility are all conditions these pilots have to deal with.
Often, the stricken climbers are experienced and well-equipped and have simply been caught out by the elements.
But sometimes, say the air crews, walkers are alarmingly poorly dressed, trying to ascend routes like the knife-edged Crib Goch in freezing temperatures without ropes, ice axes or suitable footwear.
A few days ago this crew airlifted two stranded walkers off the freezing mountain. They were dressed in little more than tracksuits and trainers.
Captain "Sticky" Bunn and colleagues have been busier than usual
Suitably clad in several layers of clothing against the bitter cold, we took off from RAF Valley in a Sea King helicopter.
Not unlike Dr Who's Tardis, the Sea King is deceptively large, with enough space inside to take 17 casualties.
In charge at the back of the aircraft is winch-man Ed Griffiths.
Not only is he the brave soul hanging off the end of a cable, plucking stranded climbers off the mountain, he is a fully qualified paramedic - with a big badge to prove it on his flying suit, lest anyone forget it.
His medical skills and a kit bag that would not look out of place in an A&E department help transform the old Sea King into an airborne clinic.
Ed, Sticky and co are always busy but in recent days they and the other search and rescue crews around the UK have been responding to a much wider range of emergencies, all because of the heavy snow.
A dash down to mid-Wales to evacuate a seriously-ill man from his rural home to hospital is exactly the kind of mission these crews now find themselves doing, as the more conventional emergency services are blocked by the snow.
And it is not just here in Wales - across the UK Sea King crews have been rescuing stranded motorists from their cars, airlifting heavily-pregnant women to hospital as well as coming to the aid of walkers and climbers overcome by the conditions.
The RAF says its search and rescue teams have been called out roughly twice as many times already this year compared with early 2009.
That is a statistic the squadron leaders say they can deal with but their resources are clearly being stretched.
These ageing Sea King helicopters will, sooner or later, need replacing and with defence cutbacks the very future of the squadrons is far from secure.
If nothing else, what the events of the last two weeks have shown is that when the snow and ice proves too much for the rest of us, there is a big yellow 'cab' - with a man called "Sticky" in the driving seat - that can usually get through.