The experimental and theoretical investigations of cold fusion, performed during the year after the discovery of this phenomenon, are reviewed. The results, obtained by different groups, concerning the detection of neutrons, $\gamma$-rays, and charged products of the reactions as well as analysis for the content of tritium and helium and calorimetric analysis are summarized. Information about experiments on the fracture of substances containing deuterium is presented. Different attempts to understand the mechanism of this phenomenon are discussed. An example of a substantially nonequilibrium mechanism, connected with the acceleration of ions in strong local electric fields, generated when hydrides fracture, is studied.