"It is not sensible in a country with an average temperature of 41C in June and July, a midday temperature of 50C and, above all, extremely high humidity," Tummers said.
"Tourists are advised not to travel to Qatar in the summer months and inhabitants leave the country en masse during this period.
"[So] the summer months in Qatar also do not provide suitable conditions for a festival of football such as the World Cup should be, including for the supporters."
When Qatar was announced as host, German World Cup-winning captain and coach Franz Beckenbauer voiced concerns about the health risk the heat could pose for players.
However Tummers insisted that by switching the dates the weather concerns could be countered, while players might be in better condition than if the tournament was held in its traditional slot at the end of a gruelling European season.
"Space will have to be made for the tournament, even though many countries already have a winter break," the secretary of FIFPro's technical committee added.
"In Europe, competitive matches will have to be played in August and the second half of May and the first half of June.
"If you look at what happened last weekend with weather problems in Europe because of heavy snowfall, you could see this as an advantage rather than as a problem.
"And it might, perhaps, turn out that the players will be fitter at the start of a winter World Cup than was the case last summer at the World Cup in South Africa."
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