UK scientists are warning of the "potentially deadly" effects of extreme temperatures, as Europe braces itself for a record-breaking summer heatwave.
Temperatures are in parts of Spain, France, Germany, Switzerland and Belgium this week, as an enormous reservoir of warm air from Africa is pulled north over Europe.
Meteorologists have placed more than half of France on alert, with charity organisations patrolling the streets of Paris to provide water to homeless people.
Exams have been postponed for 800,000 schoolchildren, and organisers at the Women's World Cup could be forced to implement Fifa heat precautions - which include holding cooling breaks during matches and postponing games if the heat is too intense.
In Spain, one forecaster with high humidity making it feel like 47C.
While there is no universally accepted definition of a heatwave, the temperature and humidity combinations forecast for parts of Europe are "cause for real concern", according to Dr Tom Matthews, Lecturer in Climate Science at Loughborough University.
It is feared that this heatwave could be as bad as the Europe-wide heatwave in 2003 which claimed 20,000 lives.
"A lot has changed in preparedness since the infamous 2003 heatwave, but nothing should be taken for granted," said Dr Matthews. "These conditions are potentially deadly."
Professor Guillermo Rein, Professor of Fire Science at Imperial College London, warned that the heatwave could increase the number of wildfires across Europe.
"Heatwaves quickly dry out the vegetation and make it more susceptible to ignition and spread of fire," he said.
"The longer and the hotter the heatwave, the drier the vegetation gets and the larger the number of wildfires."
Professor Rein added that it is way too late now for prevention policies such as vegetation management or creation of firebreaks, but camp fires and barbecues could be temporarily banned.
Meanwhile, Professor Janet Barlow, Professor of Environmental Physics at the University of Reading, warned that city-dwellers may experience the most extreme temperatures, due to the creation of "urban heat islands".
This is when the centre of a city is much warmer than the rural surroundings, due to heat becoming trapped in buildings.
"London can be up to 9C warmer than the countryside at times," said Professor Barlow.
"In the UK a lot of our buildings were built for Victorian climates, and they're not even withstanding the heatwaves of today let alone the climate change of tomorrow."
Professor Robert Wilby, Professor of Hydroclimatic Modelling at Loughborough University, added that major urban areas are literally "hot spots" of risk.
"Those living and working within low income communities of rapidly expanding cities in the tropics are globally the most vulnerable,” he said.
The scientists agreed that climate change is almost certainly to blame for the extreme temperatures across Europe - and it's only going to get worse.
"An increase in heatwaves is one of the clearest impacts of climate change," said Professor Hannah Cloke, natural hazards researcher at the University of Reading.
"Killer heat events of this kind will become even more widespread by the middle of the century in Europe, but this outlook could get worse unless action is taken to curb future greenhouse gas emissions."
Dr Friederike Otto, Acting Director of the Environmental Change Institute at the University of Oxford, agreed that the likelihood and intensity of heatwaves are increasing due to climate change.
"In Europe we've seen from a doubling last year in Dublin to an increase in orders of magnitude in the Mediterranean," he said.
