Can you use dry ice in a cooler, and how do you pack it safely?

Yes, dry ice works great in a cooler — it stays cold longer and won’t make things soggy. But handle it carefully: never seal the cooler airtight (leave the drain plug open or crack the lid) because sublimating CO₂ can pop the lid off. Pack dry ice at the bottom, then a layer of cardboard or newspaper, then food to prevent freezing. Use insulated gloves, and keep the trunk cracked if driving. Dry ice evaporates about 5–10 pounds per 24 hours in a decent cooler.