Used typically in life sciences and healthcare or premium food product cold chain logistics, dry ice is solid carbon dioxide that melts into a gas rather than liquid through a reaction called sublimation. It's classified by airlines as a hazardous material, meaning it requires special handling for packaging and loading on an aircraft. It can be packed in a carry-on or checked bag as long as it complies with regulatory guidelines, for example that it be packed in a non-airtight container labeled "dry ice" or "carbon dioxide, solid."
