And if you felt sorry for the dancers bedecked in heavy, hot-looking, Carnival attire whom the organisers had shipped in to entertain the crowds at the finish line, you wondered if the runners would cope at all.

But Yiu, who put her career as a nurse on hold to focus on her Olympic dream, said the 35-degree heat hadn’t been the problem.

“I’m happy that I got my PB, but it’s a pity it was just a few seconds off the Hong Kong record," she said.

“The heat was better than expected, at least there was some wind, but of course it was quite sunny today.”

WATCH: relive the action involving Hong Kong athletes on Day 9 at the Rio Olympics

That wind blowing off the sea as runners did three laps up and down the bay was Yiu’s biggest issue. She was well down the standings in the front half of the race, 88th after 10km and still 76th at the halfway point, but relentlessly charged past opponents over the last 20km.

Tentative Christy Yiu preparing for a scorching run in Olympic marathon

“For the first 10k I think my pace was good but after there was quite a big headwind. I ran alone from 10 to 15k and that was quite slow, it’s hard to chase back the time. Even when I turned with the wind behind me the first half dropped a lot.

“Afterwards I tried to follow the pack, they were running slower and slower and i chased them down one by one.

“In past championships I’ve been chased down by the others, this time I’m happy I still had the power.”

The Hong Kong Amateur Athletics Association and HK Sports Institute have had specialist marathon coach Shinetsu Murao of Japan working with Yiu since 2014, and he’s been working her furiously ever since, leading to her previous PB, 2:38:24 at the Prague Marathon last May, four minutes inside the Olympic qualifying time.

He sent her to compete at the Beijing Marathon this time last year to get a taste of the brutal heat he expected in Brazil.

Colleague Anthony Giorgi, the head athletics coach at the HKSI, paid tribute to the Japanese coach and is hoping Yiu will be even faster in four years’ time at the Tokyo Olympics, despite her relatively late age.

“She did a great job, and Shinetsu has too. Christy’s a good runner in these conditions – she’s tough and he’s prepared her to handle these conditions and she’s done an outstanding job.

“She’s only a beginner really, she’s only been going two or three years [in the marathon], so if she can stretch it out that bit longer, Tokyo could be a great opportunity for her to push for top-20 or -25 and go low 2:30s.

“Hopefully that Hong Kong record will come – it’s a good record by Maggie Chan – but hopefully she’ll get that in the next year or two. But you come here to participate in the Olympics and try to get as high as you can, not necessarily chase times.”

WATCH: Christy Yiu Kit-ching shares how her husband helped realise Olympic dream

And Yiu said the Olympic experience had been even better than she expected, with a terrific atmosphere on the streets of the city.

Jemima Sumgong dodges protester to win first Olympic marathon gold for Kenya

“It was better than I’ve experienced before in major championships and the like. And there were so many girls participating, which helped me to have someone to follow.

“I hope to compete at Tokyo 2020 but I don’t know how much faster I can go – maybe I’ll answer you at that time!”

WATCH: Hong Kong Marathon 2016 - local ace Christy Yiu looks forward to the Rio Olympics

Sunday’s race was won by Jemima Jelagat Sumgong who became the first Kenyan woman to win an Olympic marathon gold medal – in a time of 2:24:04.

Bahrain’s Eunice Jepkirui Kirwa claimed silver in 2:24:13 and Ethiopian Mare Dibaba snatched the bronze in 2:24:30.