Battery operated fan! We are CW reeanctors so keeping cool is the hardest work we had to endure in the summer months.
For me, cool pans for feet and a bucket with cold water to keep your body and face cool. for the ladies in heavy dresses, those foam ice packs, are a godsend! Putting them between your legs or on crotch would cool the core temps of your body and armpits as well.
Face the opening of tent to the wind. Buy a fly to shade the top of your tent and your sitting area.
LOL thanks Debi... but that means I miss out on my 80's concert weekend at Darien Lake and I am not willing to do that.. I already started teasing my hair and sprayin the hairsrpay..LOL
Put damp washcloths in zip lock baggies and freeze them. They help keep other things cool and then are incredibly refreshing to wipe your face and neck with.
As for re-enactors - we sewed small muslin bags and pinned them under the skirts of the dresses. The put a few chips of dry ice in each sack! You don't want it touching your skin, but it feels like your own personal air conditioner under your skirt for something like a parade or ceremony.
I would suspect it would work to cool the inside of a tent too thought I never tried. Dry ice was cheaper than I expected it to be.