Haha I forgot about that! Kaya toast to us is kinda like u guys eating marmalade or jam on toast you know?
Fwiw most of us hate the humidity too.. You don't get used to it.
Max of two layers for me. And if I need to wander around in the sun (which I don't at midday) I take off my jacket. If I'm going to be sightseeing the entire day I'm definitely going to be in a t shirt or light shirt.