1. Prechill the cooler and its contents.
Place ice inside for about an hour before loading, then pack food directly from the refrigerator or freezer. If your drinks go into a cooler warm, they won't come out ice-cold.

2. Use ice and ice substitutes.
First, put both ice and Rubbermaid Blue Ice packs ($1 to $1.50 each, 888-895-2110 for store locations) along the perimeter. The combination reduces condensation buildup, which can result in soggy wrappings and food. Rubbermaid Blue Ice Flexible Ice Blankets ($1 to $5 each) are great for packing around soft items, such as sandwiches, cheese, and fruit. (All Rubbermaid ice substitutes are nontoxic.) If you want to use your cooler to chill drinks for a party, fill it with a slushy mix of ice and water.

3. Fill it up.
A full cooler stays cold longer than a half-empty one does. Fill empty spaces with ice and ice packs, and top everything with a layer of that combination.

4. Store in a cool spot.
If you're taking your cooler on the road, leave it inside the air-conditioned car — not in the trunk — and try to keep it out of the sun.