I’ve found the cure for a sleepless night in a heatwave – but it can have its drawbacks …

Here’s a tip for keeping cool overnight as the world heats up. It’s a tip you shouldn’t take unless you’re more competent than I am in practical matters. While this is a low bar, admittedly, it’s a health warning I need to share.

My mum’s place in Croatia is very old. Its walls are a metre thick. When she wanted a door knocked through one of them, the noise was tremendous. The dust and debris rose in what might have been mistaken for a mushroom cloud. There may have been dynamite involved. Having walls this thick is reassuring – any calamity serious enough to bring them down wouldn’t be worth surviving anyway.

An issue with walls this thick is that, when they get cold, they stay cold, long after the outside temperature is cracking the flags and fraying nerves. For the first half of summer this is good – natural cooling. For the second half of the summer, less so. The house becomes hot, perhaps hotter than it is outside. And it stays hot.

A few summers ago, for my mum’s 80th birthday, my family were there in numbers, and I was banished to sleep in the smallest, hottest room in the roof of the house. I didn’t dare enter it until well after midnight, but I might as well have waited until Christmas for it to cool down. It was like a bloody tandoor in there. The one little fan I had sweeping my sweaty body like a dim searchlight had no impact. Someone suggested I put some ice in a bowl beneath the fan. It helped a bit, but not much.

On the second night, I went big on the ice – very big. I found the biggest, deepest oven tray I could fit in the freezer, filled it with water, and left it there all day. Come bedtime, I hauled this iceberg of mine up the stairs and balanced it on a chair just below the fan. It started to crack alarmingly, like a glacier in the spring, but the air was soon deliciously cool and I fell into the deepest, smuggest sleep.

It was a slumber so deep that, when I awoke in the dark hour before dawn in need of a wee, I quite forget where I was, stumbled, fell and upended the tray, soaking the bed and floor, and permanently breaking the fan. But God, it was good while it lasted.