PARIS - Europe sizzled and soaked alernately as a deadly heatwave broke down into storms over parts of the continent amid warnings that temperatures would peak again.

The sweltering weather hit particularly hard in France, where the government issued warnings on radio and television after the number of reported deaths attributable to the heat reached 22.

The death toll raised memories of a fatal bout of baking temperatures that killed 15,000 people in France and more than twice as many across Europe in 2003.

"The heatwave is going to last," said France's Health Minister Xavier Bertrand Saturday, stressing that the priority was to watch out for people living in isolated circumstances who are particularly vulnerable to the heat.

Though temperatures dropped in parts of northern France, weather authorities said the respite would be short, warning of a further peak on Wednesday.

Those who died in France this week included 10 people aged 80 to 94, as well as labourers at work and a 15-month-old baby.

National radio broadcast messages to the elderly on Saturday, explaining the effects of the heat and how to combat them and giving a telephone advice-line number.

French forecasters have placed the eastern half of the country on "orange" alert -- the second highest level. Temperatures were expected to reach 38 degrees Celsius (100 degrees Fahrenheit) in the Rhone valley, though cooler weather was forecast for Sunday.

Violent storms struck the Dordogne region of south-central France overnight, killing a motorcyclist who ran into a fallen tree. Scores of firemen were mobilised and lightning caused half a dozen forest fires.

Air quality authorities in northeastern France said levels of pollutant ozone chemicals in the air had exceeded recommended levels for four days running in the heatwave, though the levels returned to normal later Saturday.

More than 30 people are believed to have died since the start of the week in western Europe.

Spain is used to such temperatures, but six provinces of the country were nevertheless on alert this weekend after three heat-related deaths, as the thermometer was expected to nudge 40 degrees Celsius.

A German truck driver in Austria died in his cabin of a heart attack brought on by the high temperature which reached 37 degrees Celsius in parts of the country, rescuers said.

Austrians have this summer experienced a soaring number of restless tropical nights, defined as nights when the temperature passes 20 degrees Celsius, meteorological officials said.

Hungarian authorities distributed water in busy parts of the capital Budapest to prevent dehydration and trains across the country were ordered to lower their speed owing to problems with the tracks caused by heat.

In Britain forecasters warned that the present relief, welcome after Wednesday -- which saw the hottest July day on record -- was likely to be followed by another heatwave next week.

"We will have another heatwave similar to this week," said forecaster Steve Randall from the Meteorological Office. "The weekend will be cooler with a risk of thunderstorms -- but temperatures will still be above average for the time of year."

In Italy temperatures were set to reach 40 degrees Celsius over the weekend, and the regions of Liguria in the northeast and Umbria in the centre were placed on the highest level of alert.

In Berlin the building union IG Bau launched a publicity campaign under the slogan "Don't Get Burned", and distributed tubes of sunscreen cream at work-sites.

The heat eased meanwhile in Belgium, where 15,000 people packed into trains to the seaside on Saturday morning, despite rainstorms in parts of the country.