I *think*
It's because women sit on the top of the bog-lid while arsing about in the bathroom; painting their toe-nails and the like, so it is warmer for those occasions, which invariably take women longer than having a shit.

I've recently had a cast on my leg due to a fucked ankle, and needed to sit down to take my trousers off and put this bag-thing over my leg to sop my cast getting wet, and can confirm sitting on the top bog seat when you've just got out the shower is fucking horrible, I used to chuck my towel over it.
( Slippery Mick ‏, Sun 3 Jan 2010, 16:23, Reply)