If you do one thing this week ... go wild swimming

The best wild swims are an escape from the heat, noise and pollution of summer in our towns and cities. I took the plunge in a gravel pit behind the M25 - where will you go?

5.30pm, July, the M25. Cars sat nose to tail, wheezing hot diesel fumes, which mingled with the exhaust raining down from the Heathrow flight path. The sun beat through the windscreen making us sweat. Everything smelled of dust.

We had been on the road for seven hours, and the prospect of spending two more analysing the back of a lorry somewhere near Staines was unappealing. I made a break for the exit towards Heathrow Terminal 5.