Oh man, I totally relate! I live right smack on the equator and it's summer
all year round. I wish I had the luxury of spring and autumn, and throw in a bit of winter to keep us all cuddling, but no. It's hot and humid, generally about 32 celsius and and humidity is between 75-80.
Which is mainly the reason why I run at night, or at least, after sunset. But I do exercise videos in the day, and going to the gym is fine because it's all air conditioned (though no budget for membership-argh!).
As long as you keep yourself hydrated, you should be okay. There are times where I run in the late afternoon and feel completely dizzy extremely quickly because of lack of hydration.
Alternatively, you could join a dance class, aerobics class, or (this one I wanna do) martial arts class. It'll be indoors and you'll still be working out.
You could make this a summer routine, so your body doesn't condition itself to the exercises your normally do and it would shake things up a bit.
