Wearing less wool helps, though I've noticed that a wool kilt compared to a non-wool kilt isn't a bad as a wool pair of trousers compared to a non-wool pair of trousers.

It's also important to wear less upper dress, i.e. cut the argyll and just go with shirt and vest. And don't forget short sleeves, or simply rolling your sleeves up!

Going regimental could help but, what do I know?