Many fear that next year’s Olympic Games will be the hottest and most humid in the modern era. It is perhaps instructive that in 1964, the last time Tokyo staged the Olympics, they opted for a start date in mid-October.

This time they are set to open on July 24. The temperature on that date this year was recorded at 34 degrees. Similar temperatures were registered over the rest of the Olympic period and in the last few weeks there have been reports of some 50 heat-related deaths in Japan.

The Japan Times, an English language newspaper in Tokyo, recently carried an article by University professor Takeo Hirata, a special advisor to the Japanese Government on the Games, entitled: "Beating the heat at the Tokyo Olympics."

"My primary concern was Tokyo’s summer heat and humidity that would impact all participants, athletes staff and spectators," he wrote. 

"This challenge would call on the best of Japanese expertise, innovation and imagination."

Among the countermeasures are large scale towers dispensing ultra fine mist. Similar technology was employed to counter the extreme humidity during the 1996 Olympics in Atlanta.

Warnings will be distributed using digital technology and in a range of leaflets which organisers say "comport with the style of each culture". They are using the term "heat illness" rather than heatstroke to try and alert people to the dangers posed by high temperatures.

The marathon route will be treated with a special coating designed to reflect infra-red rays. Toshiiko Seiko, who ran the marathon at the 1984 Games, and Paralympian Nobukazu Hanaoka took part in tests which organisers claim reduced the road surface temperature by ten per cent. The process will also be used on spectator walkways and runners may also wear ice jackets.

Trees along the route will not be cut back in a deliberate attempt to provide more shade for spectators and buildings will be asked to open their air-conditioned ground floors to spectators. It will be interesting to see how many rise to watch the races which begin at 6am. The runners will need to rise in the small hours to prepare for the race, although marathoners are used to unusual start times more than most.

On the opening day of the International Association of Athletics Federations World Championships in Doha next month, the women go to the starting line at precisely 11:59pm local time. The walking events are slightly earlier at 11:30 pm.

In the stadium, competition does not begin until late afternoon and the entire Championships are later in the calendar year than ever before.

The events in Doha will be under intense scrutiny, not just in their own right but because the FIFA World Cup is fast approaching. That begins in November 2022, again much later than it has ever been before, forcing an unprecedented re-arrangement of the entire global football calendar.

The choice of Qatar for these major global events is arguably the most controversial since Mexico was selected for both the Olympics and FIFA World Cup in the 1960s.

Sports Illustrated included Mexico 1968 in its top five '"worst" Olympics and branded the decision to take them there as "the most mystifying decision in Olympic history".

When the Mexicans had presented their bid in 1963, they claimed Mexico’s altitude "is not harmful to athletes". 

"This preconception is a problem that has been artificially created," bid officials added. "The altitude in no way affects a person of normal health."

Yet academics such as Ernst Jokl of the University of Kentucky forecast "cardiac difficulties in the 10,000 metres and marathon".

Onni Niskanen, the Scandinavian running guru who coached Abebe Bikila to double Olympic marathon gold, was said to have predicted "there will be those who will die".

Thankfully there were no fatalities in Mexico but the majority of endurance gold medals went to athletes who lived and trained at altitude. The 10,000m finished with Australia’s Ron Clarke lying on the ground as oxygen was administered through a mask.

Every Olympic Games since then has been held at sea level, although both the 1970 and 1986 FIFA World Cups were held in Mexico. They will also co-host in 2026 with Canada and the United States.

Researchers have suggested that the last four years have been the hottest on record. "Climate projections suggest the planet could warm by three or four degrees by the end of this century which could have major ramifications for outdoor sports everywhere from recreational weekend joggers to elite athletes competing on the biggest stages," wrote Rick Maese in the Washington Post only last month.

Throughout mainland Europe, temperatures in June were unusually high. They even sweltered on the banks of Lake Geneva as the new "environmentally sustainable" Olympic House was opened.

At this year's Summer Universiade in Naples, crowds at outdoor events were sparse, including open air events such as diving, while few braved the midday sun to watch the tennis in uncovered stands on the bay of Naples. By contrast, indoor arenas for gymnastics and swimming were packed.

Events around the world are taking a fresh look at how to deal with the changes in climate. The Australian Open, the first Grand Slam tennis event of the year, introduced a new extreme heat policy in 2019. Air temperature, radiant heat, humidity and wind speed were all used to generate a reading from one to five. When the scale hit four, players would be allowed an extended break. At five, play could be suspended. 

Regulations note that "the decision to suspend play is made at the referee’s discretion". There was an option to continue the match with the roof closed on show courts.

Temperatures in 2018 had highlighted the extent of the problem.

"I think there are certain days where you have to as tournament supervisor, recognise you might have to give the players a few extra hours until the temperature comes down," Novak Djokovic said at the time.

They’ve had the option to put the roof on Centre Court at Wimbledon since 2009. It is mostly used to avoid the rain, although in 2015, with temperatures approaching 30 degrees, the decision was taken to close the roof. It is a measure that is now also available on number one court.

The US Open at the end of August has often been susceptible to rain delays. Now it too has a roof. In Paris, the Philippe Chatrier Court at Roland Garros is expected to include a roof in time for the 2020 French Open.

Other extremes of weather affected another big French showpiece in 2019. During stage 19 of the Tour de France, hail, flooded roads and a landslide in Val d’Isère forced organisers to curtail the race.

"There was no other solution," insisted Tour de France director Christian Prudhomme. "There were strong storms and hailstones. We needed to alert the riders so we had to send a motorbike to alert them to stop because a few kilometres later, there was a landslide."

The following day’s stage was also slashed to cut out two significant climbs as a safety precaution.

In the early years of sport, athlete welfare was by no means as well-developed.

The 1912 Olympic Games in Stockholm were known as the "Sunshine Games" and it was not necessarily a positive accolade.

The football final was held in July, yet the playing kit they wore had been designed for matches played in winter.

"The weather was so hot, it was impossible to sit on the pitch for more than a few seconds. Bottles of water were placed along the touchlines," recalled Ivan Sharpe, who won gold with Great Britain.

In the Olympic marathon that year, Portuguese runner Francisco Lazaro collapsed from heatstroke. Advice on how to prepare for the heat was then in short supply. Tragically Lazaro died a few days later. It was said his death had been caused "possibly by meningitis possibly brought on by heat exhaustion".

Cross-country was then part of the Olympic programme and in 1924, the race took place on a scorching hot July day. Among the obstacles was a stone wall jump. Sweden’s Edvin Wide "climbed to the top and then fell down. With glassy eye and feeble limbs, he again scrambled to the top and again fell back". Eventually spectators helped carry him to an ambulance.

By 1984, when the women’s marathon was introduced to the Olympic programme, the race began at 8am to avoid the worst of the heat. It was won by Joan Benoit, who did not wear the all red used by most of her US team mates, opting instead for a specially designed silver running kit which in her case turned to gold.

Despite the early start, the heat still affected Swiss runner Gabriela Andersen-Schiess, who staggered across the line after a tortuous last lap.

"Like many viewers, I wondered whether I questioned the decision of the doctors to allow her to finish the race," pondered Los Angeles 1984 Organising Committee head Peter Ueberroth. Despite appearances, Andersen-Schiess soon recovered after medical treatment and was even preparing for another race within weeks.

Although the focus is now on heat, winter sports are equally vulnerable to climatic conditions.

In 1984, the men’s downhill was scheduled for the first full day in the Games. Blizzards forced its postponement for the best part of week before the race was finally held.