For a cooling snack, store in the crisper drawer in your refrigerator.
If you are planning on eating your apples in 2-3 days, keep them out of direct sunlight in a cool, dark place to help them stay crisp before eating.
To keep through winter, freezing is an option. Peel, core and slice apples. Dip slices in a bowl of 1-gallon of water with 1-tablespoon of lemon juice stirred in to prevent browning. Arrange slices on a plate or baking tray lined with parchment paper and freeze for a couple of hours before bagging in an airtight container or bag.