KEY POINTS:
The All Blacks took on the Italians and the weather on Saturday when they played in Marseille's sweltering conditions.
The maximum temperature was 26C with little wind, but Queensland Reds athletic performance co-ordinator Dirk Spits said the temperature could be another two degrees higher inside a stadium.
Mr Spits said some players could lose up to 5kg in body weight during a game through dehydration.
Brisbane can reach 33C on a regular basis so the training programme is worked around the high temperatures with outside training early in the morning and weights in air conditioned gyms in the middle of the day.
Mr Spits, who travelled with the Under-21 Australian side to the South of France last year, said that some players become so dehydrated they needed an intravenous drip.
Before the game players are weighed and if their body weight is lower than usual, they will have a urine test.
Players are rehydrated in the half-time break and in hot conditions, stripped down and covered in ice towels, he said.
After the game they're given electrolyte fluid containing sodium and potassium. "But some players prefer water. Electrolyte dries out their mouths."
Caryn Zinn, a senior lecturer in sports nutrition at the Auckland University of Technology, said athletes who lost 2kg through dehydration started to perform poorly.
Not all players could rehydrate during the 10-minute half-time break and it was important that every opportunity during the performance was taken to rush the water bottles on to the field. Recovering from a big game could take 24 hours. The All Blacks have a further three test matches to play in the pool stage of the tournament before the end of the month.
"If there's a few days apart, there's definitely a good chance of rehydrating."
On September 29 the All Blacks play Romania in Toulouse on the Mediterranean Coast where the conditions could be similar.
