Mont Blanc is called that for a reason.
It's been permanently covered in snow and ice for tens, if not hundreds of thousands of years.
Year-round, temperatures at 4,800m - the mountain's height - are well below zero.
Yet this week, as a heatwave grips western Europe, they hover around 0C.
Mont Blanc is starting to melt.
Lower down, as temperatures exceed 40C, wild fires have broken out, train tracks buckled and emergency services are preparing for heat related injuries and deaths.
And once again, we're reminded of what kind of future we will be living in as the world's temperature rises due to climate change.
Some changes are already guaranteed.
Take Europe's Alpine glaciers. They're history.
Given the amount of (it's just passed 415ppm - it was 320ppm in 1950) whatever we do to cut emissions now, there is enough warming "baked in" to the atmosphere that all of Europe's glaciers will melt in the coming decades.
They might still be covered in snow every winter - but are completely ice-free in the summer.
That has direct implications for availability of water for people living below alpine areas.
And while it might be manageable in wealthy Europe, glacier retreat in bigger mountain ranges like the Himalayas could impact billions.
Extremes of temperature and rainfall are also predicted to increase.
Take the current heatwave.
Not only driving up temperatures to levels that can kill the vulnerable in society, but extreme thunderstorms and flash foods go hand in hand.
And where once, heatwaves were localised events, now they're happening on a continental scale.
Time to start thinking about how we design things like roads and sewers to cope with floods, and how many trees we need to re-plant to hold back water and keep cities cool when the heatwave hits.
But while governments work to prevent future climate change getting any worse, extremes like this remind them to start adapting to the climate change we're already seeing.