As the world comes to terms with the news that 2015 was the hottest year on record, an Australian doctor is warning the people most at risk of heatwaves are increasingly the young, fit people who won't quit.
Climate and Health Alliance president Liz Hanna said 2015's salubrious record was particularly concerning for Australians.
"Australia is unfortunately ahead of the curve when it comes to warming," Hanna told The Huffington Post Australia.
"The Australian national mean temperature is 21.8 degrees whereas as far as the world is concerned, the average land temperature is about 13 degrees. The world can cope little warming but we’re already at the upper thermal limits."
While Australians are used to hearing warnings for the frail, young and elderly during heatwaves, Hanna said it was increasingly the young and fit who were being struck down by heat.
"It's the people who won't stop," Hanna said.
"That often means people who have a responsibility, maybe they don't want to let their team down, maybe they won't get paid if they don't finish the job, maybe they have animals they need to feed, maybe they need to get home.
"When you're exercising and trying to cool down, there's a battle going on inside your body. Our body usually takes heat away from your muscles through your skin, but when the air is as hot as your skin, that transfer can't occur."
She said our national mentality needed to change with the warming climate.
"There's an idea that workers are blokey young, fit guys who can handle the heat, they're not a wuss.
"This is a really dangerous idea. We really need to respect the heat."