Abstract: An electrochemical heating pad includes a corrugated sheet having alternating peaks and valleys defining channels of elongated compartments having sidewalls between the peaks and valleys. A dry mixture operable to be wetted and activated with an electrolyte to generate heat through electrochemical reactions is disposed in at least some of and preferably all of the elongated compartments. The channels are covered with a base sheet on or a porous sheet to form the compartments. The corrugated sheet is preferably made from cardboard and the porous sheet is made from non-woven polypropelene. One dry mixture of the invention includes Magnesium in a range of 80% to 95% by weight, Iron in a range of 3% to 6% by weight, and Calcium Nitrate in a range of 1% to 2% by weight. Another mixture includes about 83.5% Magnesium by weight, about 4.0% Iron by weight, about 11.0% salt by weight, and about 1.5% Calcium Nitrate by weight.