In reply to jules699:
I think it's because you have such a small contact patch and as a result have more forceon the tyre to prevent slippage, that and the force is always in the same position.
I use the rubbish tyres that came on my bike on an old back wheel that I swap in when I'm on the TT.
The other thing it supposedly does (but Ihave no experience of) is make your tyre supper smooth, which means in the wet the tyre will struggle for grip on the road.
In reply to the OP, yes a TT is very easy to ride on, and you can stand on it, as long as you don't rock the bike from side to side. As others have said, get a fan and towels
To avoid boredom look at:
http://www.thesufferfest.com/ These videos are really good.
I have the Angels video, and the Hell Hath no Fury Video (lot's of nice women's bums to watch as you grovel on the handlebars!)