By John Brunsdon BBC News Online

But while the only winter gear most of us put in our cars at this time of year is anti-freeze, explorer David Hempleman-Adams' boot contains everything he needs to fight off hypothermia and frostbite.

It is -2C outside, someway above the -90C the renowned arctic adventurer has faced, but he is taking no chances.

David Hempleman-Adams knows what cold feels like

"People don't realise that these temperatures will kill you.

"As soon as you hit sub-zero temperatures, if you are caught outside, especially if you are elderly, young, or very thin, then your body temperature can fall dangerously if you are not prepared."

Last year, several hundred motorists became trapped overnight on the M11 and other roads as an unexpected snow fall brought traffic to a stand-still.

Many were stuck dressed only in the clothes they wore to the office, and several abandoned their cars to try to complete the journey on foot.

A big mistake, says Mr Hempleman-Adams.

"The problem is that people come out of their centrally heated houses, into their heated garages, then into their nice warm cars.

"If they get caught out, they find themselves stuck wearing just a shirt and a pair of sandals."

Preparation is key

The adventurer regularly carries a sleeping bag, a flask of hot, sweet tea and a spade in his car when winter conditions are forecast.

"I know that 99.9% of the time I'm not going to need them, but for that 0.1% they are essential."

For him, preparation is the key to keeping out of trouble.

The key is that you must never assume it will never happen to you David Hempleman-Adams

"You never hear of anyone dying of hypothermia at the North Pole, because they have gone there prepared.

"But every year people die here after getting caught outside."

If you do find yourself stuck in your car, the best bet is to stay there, he says.

"Even the British army training in Norway hunker down when the temperature hits -20, because of the risk of frostbite."

Your woolly Christmas jumper is not the best thing to wear if you want to keep warm.

Wind chill

Mr Hempleman-Adams recommends putting on several thin layers, together with a wind-proof jacket.

"There's a thing called wind chill factor, which we are not very good with in the country.

"It might say minus 2 on the forecast, but the wind can make that feel like minus 15."

He also recommends wearing the minimum - perhaps one layer plus a wind jacket - if you find yourself having to dig yourself or your car out of a drift.

"The digging will keep you warm, but you don't want to build up a sweat as this can cause your body temperature to drop.

"Once you stop, you can put the other clothes back on."

And he warns against running your engine to keep warm if you haven't first checked there is no snow blocking the exhaust and forcing deadly carbon monoxide back into the car.

The explorer admits the chances of getting caught out in the cold are slim.

But you don't survive Everest, both poles, and an open-basket balloon flight across the Atlantic without a realistic understanding of risk.

"The key is that you must never assume it will never happen to you".