Dry ice is the cooler hack.

Absolutely — dry ice is the move. Chilled water won’t do much more than a regular ice pack, because water warms up fast and leaves you with a soggy mess.

Dry ice (frozen CO₂) is far colder — around -109°F — and it sublimates straight to gas, so no water buildup. A few pounds of dry ice in a decent cooler can keep things frozen or near-frozen for two to three days, sometimes longer if the cooler is well-insulated and you pre-chill it first.

One catch: do not seal the cooler airtight. Dry ice expands as it turns to gas, and the pressure can pop the lid or worse