Agreed Alun! It's quite interesting to hear how one person's 'cold' is another's 'tepid'. The skin of both these divers is undoubtedly feeling and reacting to the same temp, but the brain interprets the comfort of that temp very differently. Pretty fascinating when you think about it.
Ivan,
33C!!! That's the temp I take my tea

. Here in Wisconsin, Jon and I prefer to use 3mm suits for diving water as cold as 10 C and 5mm suits for temps below that. We've both used 7mm, but that turns out to be too bulky. We prefer the mobility of the 5mm suits to the (minimal) added warmth of a couple extra mm. When the dive is over, it's always the hands and feet that gave out first anyway.
Thanks for the words of inspiration

.
Ted