Funny I nearly put up a similar thread. I'm terrible in the heat (very fair skinned). I'm used to living near the sea, both cooler & with a breeze but currently inland in a tiny maisonette so struggling with it.
If your bedroom/workroom faces the sun most of the day and you cannot get a thro breeze with windows open in there and another room accross the way, the best thing to do is close the window, all you are doing is bringing warmer air in. Close the blinds/curtains (the continental way).
Invest in a good quality fan. The saving grace of this place is it has a large free standing fan which does actually create coolness (unlike the smaller ones which just push around warm air) and use in the bedroom/workroom.
Consider not wearing make up. I cannot wear it much anyway as I get a skin reaction.
Make sure to drink lots of fluids (way more than normal).
Can't help with the neighbour I'm araid!