In a bid to keep visitors cool in what are expected to be blistering temperatures at next year's Olympic and Paralympic games in Tokyo, organisers may deploy machines to sprinkle spectators with man-made snow.
There were at least 57 fatalities in Japan this summer as a result of searing heat.
Artificial snow is the latest strategy being considered to counter high humidity and summer temperatures that commonly exceed 30 degrees Celsius (86°F) in July and August, when the games are scheduled in the Japanese capital next summer.
A snow-making machine will be tried out at a test canoeing event on Sept. 13 in Tokyo, a spokesman for the games' organising committee said.
"We plan to produce two tonnes of snow in the test," the spokesman added, though no immediate cost estimates were available.
In 1964, when Tokyo last hosted the event, it opened in October due to heat concerns. Since 1976, most summer games in the northern hemisphere have been held in the middle of summer to fit global broadcasting and sports schedules.
Tokyo organisers tried other measures, such as vapour sprays, shaded or air-conditioned rest areas and distribution of water and ice packs, at a beach volleyball test event in July.
Officials measured the wet bulb globe temperature (WBGT), which factors in temperature, humidity, wind speed and solar radiation, as rising as high as 31.7. This exceeded a threshold of 31, at which Tokyo authorities urge citizens against exercise.
To avoid the hottest part of the day, the marathons will start at 6 a.m., with major roads on much of the 26-mile route surfaced with a resin-based material that organisers say will reflect infrared rays to cut its temperature by as much as 8 degrees Celsius.
Last month, heat concerns prompted the International Triathlon Union to shorten the distance of the run segment in a qualifying event in Tokyo for next summer's games.
Several days earlier, a number of athletes competing in the 2019 World Rowing Junior Championships were treated for heatstroke, media said.