Yes, you can put ice in an insulated cooler, but keep in mind that it’s designed to keep your drink cold for longer, so adding ice will help the cooling process but isn’t necessary. Many vacuum-insulated coolers can maintain a cold temperature for several hours without needing ice. However, if you do choose to add ice, make sure the cooler is waterproof and leak-proof, as ice will eventually melt.
For maximum cooling, pair your koozie with a pre-chilled drink or keep it in a cooler with ice when not in use.