Capello said that building air conditioned stadiums for the event would not be enough.
"It will not be easy for the players to stay all day in the hotel, you can't run around the hotel," he told reporters at an event in Dubai on Tuesday.
"It's a big problem, not only for the training, you have to spend the time, all the day in the hotel, you can't go around to relax, to do something different.
"When you stay together for long time you need to relax to do something different, not only training or playing," he added. "That's why I think it would be a good idea to play in January or February."
FIFA president Sepp Blatter has said he would not object to a January-February World Cup and UEFA president Michel Platini is also sympathetic to the idea.
On Tuesday, Asian Football Federation president Mohammed Bin Hamman, a Qatari, reiterated his country's view that June and July would not be a problem.
"I believe our country has submitted a bid where they would like to organise and host the World Cup in June/July and they have actually presented also the solution for the heat challenges," he said.
"So our country actually is ready and willing to host a very comfortable World Cup in the summer season."
But he declined to write off the winter alternative.
"The month of January is a sort of dead season, most of the leagues in Europe are suspended, they are not playing during that time," he said.
"It's not going to affect practically, the leagues or the clubs if they played the World Cup in January."
However, Barcelona president Sandro Rosell said a January/February tournament would disrupt the Spanish season which does not have a winter break.
"I have to stand up for the Spanish league. The World Cup has to be in June, July," he said. "I don't like to break the Spanish league because it's one of the leagues in Europe that continues in January."
