Abstract: A method and apparatus utilizing an exothermic reaction to generate a heated gas that warms a baby bottle, providing a baby bottle warmer that is portable, convenient to use, simple, and lightweight. In one embodiment, a heating vessel holds the baby bottle and a vessel top removably attaches to an upper section of the heating vessel. A solution release mechanism situated in a lower section of said heating vessel includes a solution container having an activating liquid disposed therein, and a device for puncturing the solution container responsive to pressure supplied by insertion of the baby bottle. A heating element situated below the solution release mechanism includes a material for exothermically reacting with the activating liquid to generate the heated gas. In one embodiment, when a baby bottle is inserted into the bottle warmer, an upper and lower unit are pressured together to release a saline solution onto a magnesium wafer.