How to stop whiteflies entering my room at night

I'm desperate. Yesterday I put up a mosquito net thinking that it would finally solve the issue, but the little bastards are small enough to make it through the mesh.

I live in a really humid area and they're just attracted by the light at night, but I can't live keeping my lights turned off all the time, and right now it's too hot to keep the windows closed.

What do I do? I'm desperate.