Lewis Hamilton has warned that boiling temperatures in Austria could expose his mechanics to possible heat exhaustion.
Hamilton's crew will work up to 16 hours on Friday preparing the Briton's car for practice and the remainder of the grand prix weekend as the mercury edges towards 40 degrees. There will be no air conditioning in the garage.
Mercedes have taken steps to ensure their staff are well looked after, with a team doctor and physio overseeing hydration by replenishing electrolytes and providing cold towels.
The heatwave sweeping through Europe is set to be an issue for team personnel in the Red Bull Ring paddock.
The thin air will also provide another problem with the track here in the Styrian Mountains situated 700 metres above sea level, the second-highest on the Formula One calendar.
"It is going to be a problem for the mechanics because they will be on their feet in the garage," said Hamilton, reflecting on the unusually high temperatures.
"The drivers and engineers will be in nice air-conditioned units, but the guys are working outside, it is going to be really tough for them."
Hamilton is bidding to win for a fifth straight race, after charging to victory at the French Grand Prix one week ago.
The Briton is 36 points clear of Mercedes team-mate Valtteri Bottas in the championship standings as he closes in on a sixth world title.
But Hamilton's dominance has become a turn-off for some fans. And the world champion believes the extreme heat might mean Sunday's race becomes a test of engineering endurance rather than a flat-out charge to the chequered flag.
"I am really going to have to nurture the car, so it is not going to be great for the fans," he said.
"The cars are too heavy, the brakes are at their maximum, and we cannot push flat out. There will be a lot of lifting and coasting. You can overtake here, but having to cool your car by pulling back from the car in front will not be a good thing.
"It will be tough in the car, too. I lost nearly three kilograms in fluids at the last race, and this race will be similar. But physicality-wise we are all trained to a high level so I think we will be OK."
Meanwhile, Max Verstappen backed Hamilton's call for the sport's owners, Liberty Media to strike a new deal with Silverstone.
Next month's British Grand Prix is due to be the last staged unless a fresh agreement is reached. Talks between both parties are ongoing.
A race in London has emerged as a contender to the Northamptonshire circuit, but Verstappen said: "Silverstone is a great track. If they want a street track in London, it would need to be an extra grand prix on the schedule."