The organizers of this summer's Tokyo Olympics plan to require athletes to acknowledge that they may face health risks or death caused by coronavirus infections and Japan's heat if they compete in the games, a document detailing conditions for participation showed Friday.

The International Olympic Committee has included such risks in a waiver that must be signed by athletes, stipulating that they take part in the games at their "own responsibility," according to a copy seen by Kyodo News.

The Olympic rings glow in the dark in Tokyo Bay off Odaiba Marine Park in December 2020. (Kyodo)

The plan is extraordinary given that the IOC did not specifically mention such risks in the waivers for the Summer and Winter Games held at least since 2008, even though some took place amid fears of infectious diseases and air pollution.

The last Olympics in Rio de Janeiro in 2016 were staged when many were worried about the mosquito-borne Zika virus, which led several golfers to withdraw from the games. In 2010, the Vancouver Winter Olympics went ahead amid concern over the global outbreak of the swine flu.

During an online conference attended by Olympic officials and athletes on Thursday, Lana Haddad, the IOC's chief operating officer, said the entry form for the Tokyo Games has been "updated to include COVID-19 related considerations," when addressing worries raised by a member of the U.S. athlete committee.

"As you must have followed the news all around the world on COVID-19, no government, no health authority can or has taken over guarantees against infections. This is a risk that we all bear," Haddad said. "This is really to provide transparency and ensures the informed consent from the games' participants."

The form for athletes and Olympic officials is intended to have them abide by various rules of the games, which are due to open July 23 following a one-year postponement. The rules include those regarding the Olympic Charter and anti-doping regulations.

With the coronavirus pandemic far from over, many medical experts have expressed concern about staging the games in Japan that will involve tens of thousands of athletes, coaches, officials, support workers and members of the press from around the world.

While the IOC has promised to hold a safe games even during the global health crisis, its COVID-19 guidelines, called the "playbook," also state that participants must be accountable for their decision to take part.

"We trust that the measures laid out will mitigate the risks and impacts involved in participating in the games, and we fully count on your support to comply with them," said the second edition of the playbook, released in April.

"However, despite all the care taken, risks and impacts may not be fully eliminated, and therefore you agree to attend the Olympic and Paralympic Games at your own risk," it said.

The playbook states that athletes from overseas will need to take tests on two separate days within 96 hours of their time of departure for Japan. They will also be tested daily, in principle, at the athletes' village during the games.

The third and final edition of the playbook will be released in June.