I had a similar problem with the heat & humidity here in Indiana, until somebody suggested I try wearing a compression shirt. I ended up getting the sleeveless HeatGear T form Under Armour, hugh difference, it wicks the sweat away so that you feel cooler. I find it odd that adding a layer actually makes you feel cooler, but hey, it works.
I always were one, then a fox compression whatever and maybe a jersey, I use to love to hate fox but they have great warm weather gear.