By Andrew Fraser

After a while it feels like your head is boiling

Anyone who reckons Paula Radcliffe only has to turn up in Athens to win Olympic marathon gold had better think again.

If my experience of Athens conditions is anything to go by, Paula's 26-mile glory bid will be like running to hell and back - and doing a few laps of Satan's kitchen for good measure.

To help Britain's Olympians prepare for the stifling temperatures they will face during the Games, the English Institute of Sport has been giving them sessions in heat chambers.

So when the EIS suggested I do some acclimatisation work of my own at the Olympic Medical Institute in north-west London, I jumped at the chance.

Big mistake.

"We have done our worst with Britain's athletes," EIS sports science boss Dr Greg Whyte warns me as he turns up the dials on the machines used to generate Athens heat and humidity at Northwick Park Hospital in Harrow.

"We know it's going to be at least 34C in Athens, but it could rise to the early 40s, which is very, very hot."

Suitably fearful, I step into the glass box, strap on a heart monitor and take my first tentative steps on the treadmill.

I have been spared the rectal probe which Whyte uses on his heat chamber victims to monitor core body temperature.

But it does not take him long to crack the whip.

HEAT CHAMBER FACTS Cost: �40,000-�500,000 Heat range: 4-34C Humidity: 20-95% Altitude: 0-3,000m Session time: 45-90 minutes Heat affects ability of muscles and brain to function Athletes will lose up to 10 litres of fluid a day in Athens - and drink 15 litres Cooling tips: ice towels, cold water on wrists/feet, ice jackets

"How about Paula's world record pace?" he suggests, cranking up the speed to 10mph with the calm authority of a James Bond villain.

"After a while it feels like your head is starting to boil," he adds as I struggle to keep my legs pumping like Paula, throat dry and sweat streaming from every pore.

My heart rate is up to an alarming 180 beats per minute.

Finally, after a grand total of 10 minutes in the chamber - a fraction of the 90 Team GB members can be subjected to - it is over.

"The one thing all athletes recognise is that heat can be debilitating to performance if you are not prepared for it," explains Whyte.

"The optimal temperature for endurance performance is 10-11C. Paula Radcliffe's first marathon world record was set in Chicago on a relatively cold day. It was also quite cool when she beat that in London.

"The chambers are so good because you can replicate the Athens environment and take a look at the strategies you are going to use during the Games.

"The work we have done has been well received and every member of Team GB should be in a position where heat won't be a limiting factor to their performance."

Competitors in Athens can take heart from the fact that the average humidity in August is a relatively dry 50%.

But Whyte believes the Greek capital's notorious pollution levels could also affect performance, particularly in events like the marathon and the triathlon.

"It is going to be a major issue. Even though pollution is coming down in Athens, it is still a very polluted environment," he says, warning that it is not just the athletes who could succumb to the harsh Athenian environment.

"The irony is that we focus all our efforts on the athletes, but those who cope worst tend to be the support crew, the media and the spectators.

"At these Games we are going to see the biggest problems in the spectator galleries, in the open outdoor arenas that don't have roofs because they weren't completed in time.

"It's incredibly hot, and guys like yourself have not undergone an acclimatisation period. You will find that the first week out there you will really struggle, and by the time the Olympics are over you will be fine!

"You are going to be sweating profusely and you'll have to increase fluid intake hugely. Avoid the heat of the day and make sure you wear clothes that are appropriate."