I tell all my patients this at physical therapy! Homemade Ice packs: 1 part rubbing alcohol to 3 parts water, gets really cold, but never hardens so you can manipulate it. every athlete (or mom) should pin this!
When ever we go to the pool or beach, I worry about sand and water droplets getting on/in my phone. So I place it in a snack size ziplock baggie. I can still use my phone through the plastic with my wet sandy hands.