Whew! The heat's on at Olympic Aquatics Centre, and the swimming competition hasn't even begun.

With temperatures soaring in London, swim coaches are complaining that it's also too hot inside the venue.

The temperature at the pool deck and in the stands has reached more than 85 degrees, about the same as the outdoor temperature Thursday.

Organizers said at a coaches meeting that they're adjusting the air conditioning to try to get the pool deck down to 80 degrees.

"They have some problem with the climate control equipment," FINA executive director Cornel Marculescu told The Associated Press. "It could be a problem for fans and journalists."

Olympics organizers held a test event at the center in March, "but they probably weren't expecting this kind of heat," Marculescu added.

Canadian coach Pierre Lafontaine was among those raising concerns during the meeting, which was closed to the media, saying that his athletes have been affected.

He said in an email to The Associated Press that the organizers "are doing a great job dealing with it. It is much better today already."

There were also concerns about the water temperature, which should be between 77-82 degrees, according to FINA rules.

After weeks of miserable weather, the sun has shone brightly on London in the last few days and raised temperatures to 85 degrees, although cooler weather is forecast next week, which should relieve the stifling conditions.

The $475 million aquatics center will stage swimming, diving, synchronized swimming and part of the modern pentathlon. The distinctive 525-foot long sweeping roof - designed by Iraqi-born architect Zaha Hadid - is considered the signature design feature of the Olympic Park.

When it is filled to its capacity of 17,500 on the opening day of competition Saturday, the temperature is likely to rise a degree or two again.

Organizers have sent heat warnings to people with tickets to aquatics events, advising them to dress accordingly and stay hydrated - either from the free water provided at coolers around the venue or by buying bottled water.