Further severe thunderstorms were expected across Europe on Sunday after a day of deadly storms on Saturday.

A man died after being struck by lightning on the Babia Gora mountain in southern Poland. The tourist was hiking down the mountain at the time. Another three people were injured in the same region.

In France, 11 people - 10 of them children - were injured after being struck during a birthday celebration at Parc Monceau in central Paris. The adult and three of the children were reported to have sustained life-threatening injuries.

In Germany, 35 people were injured at a children’s football match in Hoppstaedten, western Germany. Three of the injured were in a serious condition.

Major thunderstorms are not uncommon at this time of year, but a low pressure centre is covering a large swath of the continent. High surface temperatures and cold air aloft, allowed cumulonimbus clouds to rise more than 10,000 metres through the atmosphere on Saturday.

This mass ascent of air causes it to cool and condense, forming water droplets and ice pellets. Frictional forces within the clouds cause a build-up of static electricity which is eventually released as a discharge, either between clouds, into the surrounding atmosphere, or down to the ground.

The toll of deaths and injuries was probably higher than would normally be the case because the storms happened at the weekend, when many people are outdoors, making the most of the warm weather.

Trees are a danger

The approach of a thunderstorm should act as a warning to take cover. A solid building with plumbing, or a motor vehicle are safe places to shelter. Unfortunately, many people, when caught in the open, choose to shelter under a tree, which is the wrong move.

Although a tree will give shelter from the rain, lightning will strike any object which stands above its surroundings.

If caught in the open, it is safer to remain where you are and crouch down with your heels touching, your head between your legs and your hands over your ears.

At that point, it is also worth bearing in mind that 90 percent of people who are struck by lightning survive, although 80 percent of survivors will suffer serious, life-threatening neurological and internal injuries.

Estimates of the number of people killed globally each year vary from 6,000 to 24,000 but at least 10 times that number are injured, as lightning strikes are rarely fatal. This is because the heat caused by the high voltage passes through the body very quickly.

The best way of avoiding lightning strikes is to make use of weather forecasts and to watch for any building storm clouds.

Thunderstorms were widely reported on Sunday morning, with clusters in western and northern France, northeastern Italy, central and northern Germany, and around the Ligurian Sea.

Forecasters expect further storms to develop more widely during Sunday afternoon and evening, in response to high afternoon temperatures. Further storms are expected on Monday.

With reporting by Al Jazeera's Richard Angwin.