Ecu waterproofing

Does anyone know whether you could put interior and exterior ecus in water proof bags and do them up or do they need to breath/ or will they overheat? Im personally on about a td5 btw. Thanks

IMO dont bother with such thing.....i dont think u'll be able to seal any bag around the ECU and connectors as to totally water proof it.....then this bag will just not let the ECU to dry if eventually it got some water or even more it will generate moisture/condensation.........anyway Disco's are'nt designed to be submarines