A Spanish man who fled a wildfire with his clothes in flames after trying to dig a trench to protect his town was in serious condition in hospital but managed to communicate with his wife, a family friend told Reuters on Tuesday.

Angel Martin Arjona ran out of towering flames after the wind changed direction and fire and smoke engulfed the digger he was operating in the northwestern town of Tabara in Zamora province, a scene caught on video by Reuters.

Arjona, 50, the owner of a construction equipment firm, suffered severe burns and was given emergency first aid on the spot before being airlifted to a specialist burns unit in the nearby city of Valladolid, local emergency services said.

Family friend Jose Manuel Taba said he was in serious condition but had communicated with his wife in the early hours of Tuesday.

"He is in a very serious condition but he is conscious. He has spoken to his wife or made gestures to her," Taba told Reuters. "We will have to take things step by step, it's a very complex situation."

The fire around Tabara has been brought under control but others continued to rage nearby, including around a wind farm. The blaze started in Losacio, Zamora, and has caused two deaths, left three people critically injured and seen more than 6,000 people evacuated, authorities said.

Rafael Reyes, an official from Madrid's regional firefighting service, urged anyone who saw smoke to call emergency services immediately.

He said civilians should not approach an active wildfire and said even firefighters were forced to wait for "a window of opportunity" to act on them. However, he said civilians could move to tamp down fires in early stages.

"If it is a small, controllable fire just starting, we should try to put it out with earth, sand, water or by cutting some green branches and trying to suffocate it by hitting the base of the flames," he told local TV station Antena 3.

Wildfires raged across parched countryside in France, Spain and elsewhere as a heatwave that settled over southern Europe last week edged northwards, with temperatures provisionally exceeding 40C (104F) in Britain for the first time. Southern and western Germany and Belgium were also braced for potentially record-breaking temperatures.

Although temperatures in Spain have dipped from the weekend's heatwave, firefighters are battling 24 active fires. Temperatures are expected to rise again from Wednesday.