Digging around at night in a cooler can be a perilous task. You'll need a light source, and if one isn't handy you'll have to use your phone. This greatly increases the odds of your mobile slipping out of your hand into the icy unknown.
Consider these LED cooler lights that can be fully immersed in the ice and water instead. At only $15, they'll light up your cooler in an array of lights (6 choices, to be exact), and you won't have to worry about you or your guests at the party or campsite unknowingly grabbing a bottle of Smirnoff instead of a delicious stout beer.