Lying awake in bed, I struggled to sleep. My skin was sticky with sweat even though I'd showered not long ago. The fan, whirring at full blast, offered little relief. This was my second day trying to wean myself off the air-conditioning, and I was failing miserably.

Before you roll your eyes, hear me out: My bedroom, by quirk of design, is the warmest room in the house. It is a greenhouse in the morning and stuffy on most evenings. Which is why I tend to switch on the air-con before I sleep, setting it at 28 deg C (the room actually cools to 27 deg, according to my mercury thermometer).