Well I have 0 experience outside the cold temperate climate so just reading the word "equator" made me sweat profusely and maybe faint a bit from the heat :D But that might be just because I'm sitting too close to the wood burner, sipping mulled wine with quince and currants :)
I think the original-original (you know, like the OG Homo :D) humans survived mainly in climates similar to yours, as the energy and tools requirements are very very much lower over there. Of course, each place has its up and downsides and I really, really enjoy the fact humans had the adventurous spirit to explore, adapt and evolve over the last 2 million years.
Otherwise, I cannot imagine 8 billion people crammed along the tropics... brrr got the goosebumps just by thinking about it!