Exceptionally high temperatures have led to a heightened risk of forest fires across the country, leading Portugal to declare a level three alert, the third highest of four levels.
Measures in place include a ban on walking through or remaining in woodland areas, including forest, woodland and rural trails. Setting off fireworks has also been prohibited.
The FCDO said: “During the state of contingency, you can be prosecuted if you do not comply with these restrictions or if you do not follow the instructions of the civil protection and police authorities.”
Temperatures in Portugal have hit 40C and The Guardian reports 29 people injured as blazes were battled.
Last month, 96% of Portugal was classified as being in extreme or severe drought. High winds are expected to fuel the spread of fires in the coming days.