So it came to pass that, closely observed by an audience of sniggering young women possessing the combined weight of your average rugby forward pack, I found myself single-handedly pushing a three-tonne minibus. It moved a few inches. The girls stood in a row, hands in pockets, as the engine revved, the wheels spun, and I strained and skidded and swore in the starlight. "It's not moving, " they called helpfully, enjoying the entertainment, as blood vessels popped in my eyes and my lower back groaned.

Now, I don't blame schools. I admire them for attempting half the things they do in the current climate, and I think teachers who accompany school trips deserve the VC as a matter of course: not for handling the children, but for coping with the nonsense they face from parents. But I do think they should call parents' bluff, and drop the vague euphemisms employed to such devastating effect by the fear industry. Instead they should write letters saying: "We have calculated that the odds of a Scots child making a single London Tube journey being killed by a bomb are approximately 50 trillion to one, roughly five times higher than the chance of your family being wiped out by a meteor strike. If, nevertheless, you wish your child to walk three miles instead, breathing diesel particulates (odds of causing cancer: one million to one) or facing the risk of being run over by a bus (odds: 1000 to one) then please sign the enclosed form."

Signs of a backlash against the safety orthodoxy are emerging. Extreme sports are a growth area. A book called The Dangerous Book for Boys is a surprise number one in the Amazon book chart, exhorting our sons to climb trees, build treehouses, fire catapults and build go-karts. We must hope a Dangerous Books for Girls will follow soon. Meanwhile, David Yearley, the play safety manager for the Royal Society for the Prevention of Accidents, thinks too much emphasis on safety has made play areas boring. "Children need some risk in their play to help them to learn and to develop, " he has said.