Why we pick the wrong holiday destinations

Having returned from a fortnight’s break, I wonder if we get holidays all wrong. In northern Europe, the custom is that you head south to spend time on the beach. But equally, there is such a thing as too damned hot, especially if, like me, you have a healthy dose of Celtic ancestry.

To avoid this, you need to study what is called the ‘wet-bulb temperature’. This is a measure of temperature which accounts for the cooling effect of evaporation. At 100 per cent relative humidity, the wet-bulb temperature is equal to the dry-bulb temperature shown on weather forecasts. At lower humidity the wet-bulb temperature is lower, owing to evaporative cooling, a mechanism all humans other than Prince Andrew depend on to reduce their body temperature. This explains why I can wander around Phoenix comfortably at 100°F, while I find London at 90° uninhabitable.