How to protect your chest lights?

I've recently bought an excellent set of Fettronics chest lights. Due to the fact you got so hot wearing the costume and tend to sweat a lot (well I do anyway) how do people protect their chest light circuitry from moisture?

Thanks,
Phil

My board is just electrical taped to the back of my armor. I wear a t-shirt under my flightsuit and I've never had sweat go through my shirt, the flightsuit, and the vest to get the circuit board wet.