Rajiv Bahl, an emergency medicine physician in central Florida, breaks down when to use a cold ... "warm packs," not heat packs, noting that some people misinterpret heat as "hot" and end up ...

Commercial heat packs (containing iron and water, or supersaturated sodium acetate) and cold packs (various ammonium salts) can be used to show exo- and endothermicity. Heat packs that contain iron ...