Visiting Britain for the Olympics? You may not have heard. Temperate Britain isn’t pleasant at the moment. I just discovered the dead Christmas tree in the garden. It had been sitting in a pot since January. The pot had filled with water several times over, a clear case of over-hydration. Just another casualty of the UK’s temperate climate.

The problem is humidity. Wiki “Humidity is a term for the amount of water vapor in the air.”

I just came back from Sicily. After a few days away I’d grown used to something far more suited to the human condition. Low humidity. Yes, it’s rained non-stop all year in the UK. Nothing odd about that. We’d already missed a few wet seasons. I know there’s no law of averages, but rain does have to go somewhere, and the UK is always in the drop zone.

Camping in Cornwall last May, and on one wet night, everything inside the usually-waterproof tent was soaked. Weather.com showed that it was a teeth-chattering 3 degrees combined with 100 per cent humidity. The air was literally condensing out inside the tent, showering my laptop with every gust of rain-laden wind.

Today in July, it’s a low 15 degrees and a high 84 per cent humidity. Cold and clammy. Compare this with Sicily where it’s 27 degrees and a staggeringly-low 8 per cent humidity. After a few days away, I can actually feel the water in the air on my skin as though it’s raining. The effect of 84 per cent humidity and low temperature is to slow you down, make you feel heavy-headed and thirsty. Joints ache. Throat is dry. Head thumps. Sinusitis.  Bleeding ears.

Okay, I’m exaggerating with that last one, but I am beating a trail to pee more than I drank. It’s the opposite to dehydration. Is there a medical condition called over-hydration. How do you cope with being cold and clammy? A Gortex duvet? A heated brolly? Something needs to be done before the Olympics become another British loo queue marathon. Or maybe they’ll have to bring in the Thames barrier to deal with the influx.