Here in the humid South of the USA I've found that if I start to get too warm in a kilt, I just walk around for a bit and the swish of the kilt will vent any warm air from the kilt. All in all, I stay very comfortable in a kilt whether my wool Stillwater or my PV USAK or my cotton MarPat PK. No doubt the lighter PV and MarPat are cooler and lighter than the wool, but I'd rather be warm in a kilt than sweating in pants or shorts.