I know a few things that help but are not 100%.
That bath oil called "Skin So Soft", as a kid my mom would take a wet washcloth sprinkled with that stuff and wipe it all over my brother and I. It helped repel the mosquitos.
Dryer fabric softner sheets. Wipe them on you, tuck them in your clothes, whatever, the mosquitos are not fond of them.
Cedar wood in your campfire, red or white cedar, both work well. But don't just throw it on the fire, you don't want the wood to just burn up. Keep it on the edge of your fire where it will smolder and smoke. Plus the smoke smells nice kinda like incense.
Gasses... I have often noticed that when next to a busy highway where you can smell the fumes, the mosquitos usually don't follow. I have noticed the same when in old landfills that have those methane burnoff pipes.