This is more of a photography tip than a fishing tip, but it certainly pertains to any electronics like GPS handhelds or things like binoculars that you may take out in the field fishing.
Many of us bring point and shoot cameras or DSLRs on our overnight fishing adventures. If you’re not careful, condensation can ruin you camera, or at least render it useless for a couple of hours.
Much like bringing a cold beverage out of the freezer, your camera will “sweat” and fog up if brought from the cool air of A/C out into a humid or hot environment. Some cameras will malfunction and actually shut off if the condensation becomes too much for the internal circuitry. The same goes for shooting in the winter: if it’s hot inside and you march right out into the cold, the same thing will happen. Let your camera get accustomed to its environment for a full hour before its first use. This image here was ruined because I forgot I had left my camera in the cooler for an hour after placing it there quickly and forgetting about it.
Do yourself a favor while out taking photos while fishing. Think about the temperature changes your delicate electronics might encounter and plan a warm-up or cool-down hiatus to avoid any unpleasant surprises.