None is the short form of Androstenone - Which is the main sexual phero.
It increases female arousal - which is good, but the bad side is that if you use too much of it, the effects go the opposite way and you can be seen as agressive, angry, pushy, creepy or just far too horny for your own good. None can also provoke an agressive/challenging response in other guys or just plain scare people away.
So this is why we balance none with other pheros like Androstenone and Androsterone which I described earlier. Using these in different proportions can offset the bad aspects of none and bring out the good. Its as simple as this - Women generally need to experience a range of feelings to become attracted to someone, men just need to get horny!
It is finding the right balance between these three main pheros and the many secondary pheros that you have to do a bit of work on to get right.
Have you read these threads:
All the basics of choosing and using pheros are well covered there. 
Yes - hot weather can affect phero diffusion. There are several strategies to offset this but in Thailand, after your pheros dry down, you may well need to apply a thin layer of lotion over your application points to slow down the diffusion. There are other posters here from very hot places who can answer this better.