A food container (e.g., tray) with a thermal reagent adhesively attached to its outer surfaces reacts with water. The attached reagent undergoes an endothermic (i.e., cooling) or exeothermic (i.e., heating) reaction in the presence of water. A burstable water pouch releases water for the reaction into a lower container (e.g., tray) when the food container is pressed into the lower container, with the pouch therebetween. A removable impervious plastic film may protect the attached reagent while in storage. Multiple reagent layers may be separated by a water-soluble plastic film to provide a prolonged thermal reaction.

A method for producing energy by exothermal reactions between hydrogen and a transition metal comprises a step 110 of depositing an amount of crystals of the transition metal in the form of micro/nanometric clusters having a predetermined crystalline structure on a surface of a substrate, wherein each clusters has a number of atoms of the transition metal lower than a predetermined number of atoms, and in such a way that the substrate contains on its surface a number of clusters that is larger than a minimum number. The method provide also performing at least once a start-up sequence is performed at least once a start-up sequence comprising the step 114 of quantitatively removing any gas adsorbed in the substrate and in the transition metal by applying a predetermined vacuum degree, a step 120 of bringing hydrogen into contact with the crystals, a step 130 of heating the crystals up to an adsorption temperature higher than a predetermined critical temperature, thus causing hydrogen adsorption to the crystals forming a reaction core, and a step of impulsively acting on the reaction core in order to trigger the exothermal reactions between the hydrogen and the transition metal in the clusters. Once the reaction started, a step 140 is provided of removing heat from the reaction core in order to obtain a determined power and to maintain the temperature of the reaction core above the critical temperature.

A nose warmer is provided. The nose warmer is made of an elongated body having an outer surface, an inner surface and a pouch formed in between. A mixture is contained within the pouch of the elongated body. The mixture is configured to produce an exothermic reaction. The present invention may further include an adhesive layer attached to the inner surface of the elongated body. Therefore, a user may adhere the elongated body to their nose, and keep their nose warm during cold weather.

A solar energy collection system comprises hollow radiation absorber(s) in an enclosure, each absorber for filling with working fluid, to absorb radiation impinging thereon and transform its energy into heat to thereby heat the fluid. The system comprises an inlet non-return valve upstream of each absorber, for allowing a flow of the fluid thereto; and an outlet valve downstream of each absorber for allowing a flow of the fluid out. The system comprises a measuring device for determining parameter(s) of the fluid within each absorber, which depends on the heat absorbed thereby; and a controller that controls operation of at least the outflow valve between its open state in which the fluid can flow freely out of the associated absorber, and its closed state in which the fluid filling the associated absorber is held therein for a period of time depending on a desired change of the parameter.

A heating element (10) comprises an exothermic layer (11) containing an oxidizable metal, a water absorption agent and water and a water-retention layer (12) having a water absorption sheet (102), the exothermic layer (11) and the water-retention layer (12) are in layers, in which the mass ratio of the content of the water absorption agent is from 0.3 to 20 parts by mass for 100 parts by mass of the oxidizable metal, mass ratio of content of water to the content of the water absorption agent in the exothermic layer (11) (water/water absorption agent) is from 0.8 to 13, and the content of water contained in the water-retention layer (12) is from 10 to 45 mass % of the maximum water absorption of said water-retention layer (12).