The long school holiday is almost here, and with it comes the annual fear that some of the children with time on their hands for week after week will almost certainly get up to some dangerous activities.

There is nothing new about this, of course. Children have always been reckless by nature. They simply can't see perils which are so obvious to adults, particularly when they are playing together in a group.

The vast majority of youngsters get away with it. They come to no harm. Others, though, are less lucky. Every summer unfortunately brings its crop of tragedies, some of which might have been avoided if the children had been more carefully supervised.

In a commendable attempt to reduce this toll some utilities and industries have begun to warn of the dangers that children face if they trespass on to their property. The other day, in a letter to this newspaper, the Quarry Products Association warned of the dangers faced by youngsters who are tempted to play around local quarries.

And today we carry a warning from York-shire Electricity for children to be kept away from sub-stations, pylons and overhead-wire poles and another from British Transport Police and Arriva Trains Northern stressing the dangers of trespassing on railway lines.

As a Transport Police representative says, people who trespass on the railway line are committing an offence and could face prosecution. Parents need to impress that on their children.

But even more importantly they need to get the message across to them that there is much more than that at stake: their life.