Can I bring a cooler as checked luggage on a plane?

Yes, but there are rules. A cooler counts as a checked bag if it’s within size limits (hard-sided up to 62 linear inches). Soft coolers work as carry-ons but hard coolers are better for frozen food. Dry ice is limited to about 5.5 pounds per passenger and must be marked and ventilated; regular ice needs double-bagging and absorbent lining. TSA will inspect it, so use a TSA-approved lock or zip ties and pack dense frozen items, not liquids.