People are being told to stay indoors as temperatures are set to surpass 40 degrees Celsius in some areas
Irish holidaymakers travelling to parts of Europe are being warned to take extra precautions amid record breaking temperatures.
Forecasters say the mercury in Spain and Portugal could hit temperatures in the high 40s.
The heatwave in the Iberian peninsula is expected to continue through the weekend, with forecasters saying the heat could surpass the 47.4 degrees Celsius temperature recorded in Portugal in 2003.
Weather alerts have been issued for most areas in Spain for Thursday, Friday and Saturday, with two provinces facing red warnings for 'extreme risk'.
Potentially record breaking temperatures in #Spain and #Portugal this weekend as the intense heat continues to build 🌡️ Last night, temperatures fell no lower than 29°C in Faro, Portugal pic.twitter.com/9dhuznxrLS— Met Office (@metoffice) August 2, 2018
Most of south Portugal is also under the highest warning level.
There are also fears the hot temperatures could see an increase in deaths across the continent.
Climate expert at Maynooth University Professor John Sweeney said temperatures of more than 40 degrees Celsius on the continent are a "very different beast" to the high temperatures that have been experienced in Ireland this summer.
For those who are travelling abroad, he advised: "Drink as much water as you can - more than you normally do.
"Make sure your ventilation is as good as possible in whatever place you're staying... slap on the factor 50 if you're going out in the sun at all."
He added: "Ideally, stay indoors, find an air-conditioned cool spot, and just read a book."