I knew my O-Level physics would be useful in the end!

Two things:

I remember reading that if you're up in the mountains in a thunderstorm the voltage gradient can suddenly build up just before a strike and cause sparks to come from your extremities.
(Settle down at the back).

Second, buying copper dowsing rods at Avebury and pointing them at the stones in thundery conditions didn't oughta be allowed.