Leave the lid cracked.

Clean it, dry it, leave the lid slightly open, and store it in a cool, dry place.

Most cooler damage comes from two things: moisture trapped inside (hello, mold) and temperature swings that warp the plastic. If you lock the lid tight for months, that trapped humidity does more damage than any demonic force. And if the garage gets hot enough, the seals can bond to themselves.

So wash the cooler with mild soap, rinse well, and wipe it bone dry. Prop the lid open an inch or two — a rolled-up towel works — and stash it somewhere that doesn’t see direct sunlight or freeze-thaw cycles. A basement corner or a shaded garage shelf beats a sunny patio.

You can also treat the gaskets with a little silicone lubricant if you’re feeling fancy, but it’s not required. The open lid is the real trick.

Don’t stack heavy stuff on top of it. Coolers aren’t shelving.