Brits visiting a popular holiday destination have been warned to expect extreme weather, with temperatures of up to 43C predicted. Spain is bracing for a heatwave that will bring temperatures usually only seen in the "height of July or August".

Experts have revealed that an "exceptionally warm air mass" is expected over parts of the country from today (June 16).

As reported by Meteored, meteorologist Nacho Espinós said: "We're expecting highs of up to 43C this week."

He warned: "Although June is the first month of summer and the heat is guaranteed across much of the Iberian Peninsula, temperatures reaching the 43C forecast for next week are not normal. Nor is it normal for temperatures in the centre to reach 40C."

Central areas like Madrid could see the mercury hit 38C.

He said: "So we'll need to pay attention to any special warnings or alerts issued by the AEMET (Agencia Estatal de Meteorología) for next week."

"Everything seems to indicate that the Cantabrian coast will be spared the extreme heat that the rest of the peninsula will suffer, as the breeze regime will be key to preventing temperatures from skyrocketing," he added. "San Sebastián, for example, will have highs of 24C/25C next Wednesday and Thursday."

Portugal could also be affected by this heatwave, with predictions of 38C in Lisbon and Coimbra.

The NHS warns that heatwaves can increase the chance of serious illness and even lead to fatalities, with young children and elderly people most vulnerable.

The main risks posed by a heatwave are:

• Not drinking enough water (dehydration)
• Overheating, which can make symptoms worse for people who already have problems with their heart or breathing
• Heat exhaustion and heatstroke

To try to stay cool and hydrated, the NHS recommended staying out of the heat if you can. "If you have to go outside, stay in the shade especially between 11am and 3pm, wear sunscreen, a hat and light clothes, and avoid exercise or activity that makes you hotter," it said.

The health body added: "Cool yourself down. Have cold food and drinks, avoid alcohol, caffeine and hot drinks, and have a cool shower or put cool water on your skin or clothes.

"Keep your living space cool. Close windows during the day and open them at night when the temperature outside has gone down.

"Electric fans can help if the temperature is below 35 degrees. Check the temperature of rooms, especially where people at higher risk live and sleep."

You should call for emergency services if you or someone else has signs of heatstroke, including:

• Still being unwell after 30 minutes of resting in a cool place, being cooled and drinking fluids
• A very high temperature
• Hot skin that's not sweating and might look red (this can be harder to see on brown and black skin)
• A fast heartbeat
• Fast breathing or shortness of breath
• Confusion and lack of coordination
• A seizure or fit
• Loss of consciousness

Spain is one of the most popular holiday destinations in the world for Brits, with more than 17 million people from the UK visiting every year.