He added: "It's fine to take a couple of days off from exercising."
Rist made a similar point, saying everyone needed to adjust daily routines to match the conditions. "Even if you are young and in good health with no underlying medical issues, this heat will affect you too," she said.
She warned that even cycling could carry risks after a week of persistent high temperatures, with people becoming faint, falling and potentially ending up in hospital. Not exactly the training plan anyone had in mind.
How is climate change affecting European heat?
Climate change is pushing temperatures higher globally, but Europe is warming especially quickly. According to the Copernicus climate service, the continent is heating at twice the global average, making it the fastest-warming continent.
That has practical consequences beyond uncomfortable afternoons and bad sleep. Europe is seeing more intense summer heatwaves, increasing pressure on water supplies and more severe wildfires.
Last year, more than 1 million hectares burned across Europe, a record level. Spain was particularly badly affected.
Those wider trends do not mean every single hot day has a simple one-line explanation. Weather still varies, and local conditions matter. But the baseline is rising, and heatwaves are arriving in a warmer system. That shifts the odds, and not in a helpful direction.
What is happening in Spain?
Spain is forecast to see temperatures peak at 38C to 39C in some areas on Thursday, though forecasters say cooler Atlantic air is moving in.
The country has already endured exceptional June heat. On Monday, Andújar in southern Spain recorded 45.1C, the highest June temperature logged in the country this week.
Spain's MoMo monitoring system, which tracks temperature-related deaths, counted 213 fatalities between Sunday and Wednesday that could be linked to the heat. That included 95 on Wednesday alone.
These figures are monitored estimates rather than final cause-of-death rulings for each case, but they are a clear signal that the heat is carrying a serious public health cost.
Where is the heatwave heading next?
Germany, Luxembourg, Switzerland, the Czech Republic, Austria, the Netherlands and parts of the United Kingdom are all facing serious heat warnings as the hot air shifts east and north.
In Germany, temperatures overnight in the southwestern town of Bad Bergzabern did not fall below 26.2C on Wednesday night. That equalled a national overnight heat record set in 2019.
Germany's DWD weather service said large areas of the country were experiencing "heat stress". DWD meteorologist Oliver Reuter said it was "quite likely" the heatwave would eventually be regarded as historic.
Luxembourg recorded its highest June temperature on Wednesday, with 38.3C in Wormeldingen. A red alert for "extreme thermal stress" has been extended across the grand duchy until Saturday night.
How are transport, events and public places responding?
The heat is now disrupting travel, sport and tourism.
- Hamburg's half marathon in Germany has been cancelled for Sunday.
- Deutsche Bahn, Germany's national train operator, is offering free ticket cancellations over the next few days for passengers who do not want to travel in the extreme heat.
- Czech Railways has advised passengers to consider postponing journeys if they do not need to travel.
- Florence's Uffizi museum has halted ticket sales until 28 June, allowing entry only to people with existing bookings.
The Uffizi said its air conditioning system could not cope with the combination of heavy visitor numbers and extreme temperatures. Inside the museum, temperatures reached 32C on Wednesday. Great art, less great ventilation.
Which countries have the strongest alerts?
Much of northern and southern Switzerland is under MeteoSuisse's highest weather alert, with the agency also warning of a "significant drought situation".
In the Czech Republic, temperatures were already well into the 30s on Thursday. The ČHMÚ Hydrometeorological Institute said the heat would intensify on Friday, with temperatures possibly reaching 40C at the weekend.
Vienna could also approach 40C over the weekend. In the Netherlands, a code red alert comes into effect in eight of the country's 12 provinces from midnight on Thursday local time, with localised eastern areas potentially reaching 39C.
The United Kingdom's Met Office has extended its red extreme-heat warning until Friday evening for parts of London and south-eastern England.
When will Italy see the peak?
Italy has been experiencing high temperatures since the start of the week, but the peak is expected on Monday. Several northern regions are forecast to reach 40C, while night-time temperatures may not fall below 29C.
Forecaster Lorenzo Tedici told Italian media that the old pattern of June heat has shifted sharply.
"Gone are last century's June days of 32C daytime temperatures and cool 17C nights," he said.
He added: "We have become so accustomed to excess that, paradoxically, today we welcome a forecast of 34C as good news."
That is the uncomfortable arithmetic of this heatwave: when 34C starts to look like relief, the scale of the problem is not subtle.
