At least 4,000 people have left their homes on the Spanish island of La Palma due to an "out of control" wildfire, with 300 firefighters tackling the blaze.
Temperatures in parts of Spain have already reached 46 degrees Celsius.
Reporter Joan Larkin in Alicante has warned the thousands of Irish holidaymakers going to Spain in the coming weeks to follow the advice of authorities.
“They're being advised by health officials here not to get complacent about such extreme heat,” she said.
“Drink lots of water, avoid caffeine and alcohol as they can dehydrate the body and to stay out of the sun between midday and 4pm.”
Spain is among several in southern Europe struggling to cope with a heatwave, which experts say will intensify this week.
The European Space Agency warned July could bring the hottest temperatures ever recorded in Europe.
Spokesperson Clement Albergel said there are serious health risks in the high temperatures.
“Very high temperatures are among the most worrying climate extremes regarding the durability of our society,” he said.
“Not only do extreme temperature give us heat exhaustion and severe dehydration, but they also raise the risk of having a stroke.
Mr Albergel said 61,000 people died in summer 2022 due to the “record-breaking heat”.
He also said there are serious economic impacts due to the severe heat.
“Think about construction for example,” he said. “In case of strong heatwaves construction sites must be stopped.
Temperatures already reached up to 40 degrees this week in the heatwave known as ‘Cerberus’, named by the Italian Meteorological Society after the mythical dog that guards the gate of hell.
A second heatwave known as Charon - after the Ancient Greek 'ferryman of the dead' - is expected to cause “threat to life”.