“Your body temperature actually drops during the night and usually at its coldest about two hours before you get up.
But when you’ve been drinking, your liver is madly metabolising all the alcohol, breaking it down to get it out of your blood stream. This is a really exothermic process which means it produces a lot of heat. Your liver is actually the main heat-producing organ in your body anyway. When it’s working extra hard you’re producing a lot more heat than usual. Added to that alcohol stops you from being able to thermo-regulate. When you’re too hot, you sweat to cool down – the alcohol stops your body from being able to do that. This combined with much more heat being produced by your liver really makes you heat up in the night.”