The World Health Organisation (WHO) expects more than 1,300 deaths from an ongoing heatwave across Europe.
Some 2,700 people died of a heatstroke in France last month.
The heatwave continues since June, with the worst affected countries being Spain and France.
Top-level red alerts, in Southern Spain continue due to temperatures exceeding 45°C (113°F).
Major power outages affected tourist icons like the Louvre and southern regions like Seville, Italy and Greece.
The World Health Organisation (WHO) said heat can make people seriously ill.
People are urged to watch out for signs such as headaches, dizziness, nausea, cramps, palpitations, excessive sweating or unusual tiredness.
“Slow down or stop activity, move to a cooling area, drink water. Seek help if your symptoms don’t improve” said an advisory from the WHO.