[dramatic music] [watch beeps] ♪ ♪ - My name is Dimitri Theodorikakos.

I'm a trail and marathon runner.

I live and train in Athens.

♪ ♪ During summer in Athens, it's extremely difficult to run during the day.

The temperatures are extremely high.

So we try either to run very early in the morning or very late at night.

♪ ♪ narrator: Summer temperatures in Athens regularly top 100 degrees Fahrenheit.

♪ ♪ Climate change will drive them up even further.

♪ ♪ Highs of 110 degrees are expected in the next 30 years.

♪ ♪ - I feel every year it becomes more and more difficult.

When the temperatures are really high, I sweat a lot, which means I lose maybe one liter and a half every hour of running.

So I dehydrate all the time, every day.

[soft music] ♪ ♪ narrator: The higher the mercury rises, the more dangerous it becomes for athletes to push themselves to the limit.

♪ ♪ [dramatic music] - Scientists say that because of climate change, by 2085, only 35 cities around the world will be capable of hosting the Summer Olympic Games.

♪ ♪ Unfortunately, my city, Athens, will not be one of them.

♪ ♪ narrator: The home of the modern Olympics is expected to exceed the safe temperature limit for elite endurance events, as will many other former Olympic cities.

♪ ♪ - All athletes dream to compete at the Olympic Games and represent their country.

♪ ♪ It's really sad for Greek athletes that they will not have this opportunity.

narrator: It's a reminder of how rising temperatures impact us all in the most unexpected ways.

- Climate change does not affect only running, but also everything to do with our way of life.

♪ ♪