Concerns over athlete welfare under sweltering conditions in Tokyo have forced World Athletics Championships organisers to start road events earlier than initially planned.
The temperature in the Japanese capital is expected to reach at least 30 degrees for the majority of the championships (live on RTÉ2), which begin on Saturday, with humidity pushing the "feels like" factor closer to 40 degrees on some days.
As a result, World Athletics has moved the race walk and marathon forward by half an hour, in order to put "the highest priority on athletes' health and safety".
The rescheduling affects the women's and men's (Oisin Lane) 35km race walk on Saturday, the women's marathon (Fionnuala McCormack) on Sunday, and the men's marathon (Hiko Tonosa and Peter Lynch) on Monday.
For the marathon, 185 water spots will be set up along the route for athletes to hydrate, more than what had been planned for the Tokyo Games.
A record-breaking team of 28 that will represent Ireland at the Championships.
Watch the World Athletics Championships with RTÉ Sport, beginning at 11.55pm on Friday on RTÉ Player, with television coverage on RTÉ2 every day starting on Saturday from 9.45am
