Hot-water bottle for at least indirectly bringing into contact with a living being, comprising at least a receiving space for holding a flowable material, wherein a closable supply and discharge opening is formed on the receiving space for supplying the flowable material into the receiving space and for discharging the, in particular cooled, flowable material out of the receiving space, wherein the receiving space is formed at least in sections by a flexible wall, wherein the flexible wall can be brought at least indirectly into contact with the living being and a latent heat storage means, wherein the latent heat storage means is arranged in such a way that a tempering of the flowable material can be effected at least temporarily by the latent heat storage means, wherein the latent heat storage means is arranged within the receiving space or is formed as part of the wall wherein the latent heat storage means comprises a phase change material, wherein the phase change material absorbs energy during an endothermic change of state due to heating and releases energy in the form of heat during an exothermic change of state, wherein the phase change material is provided in such a quantity or mass that, with a receiving space filled at least 2/3 with flowable material tempered to a temperature above the melting point of the phase change material, the endothermic change of state of the phase change material is only partially effectable at an ambient temperature of 20°C, wherein the flowable material is a liquid, characterized in that the phase change material comprises at least salt constituents, wherein the melting temperature of the phase change material is between 36°C and 70°C, wherein the phase change material comprises sodium acetate trihydrate, wherein individual wall parts of the latent heat storage means are connected to one another by shape retaining elements or shape presetting elements, wherein a shape retaining element or a shape presetting element limits an expansion of the volume locally bounded by the walls. comprising at least a receiving space for holding a flowable material, wherein a closable supply and discharge opening is formed on the receiving space for supplying the flowable material into the receiving space and for discharging the, in particular cooled, flowable material out of the receiving space, wherein the receiving space is formed at least in sections by a flexible wall, wherein the flexible wall can be brought at least indirectly into contact with the living being and a latent heat storage means, wherein the latent heat storage means is arranged in such a way that a tempering of the flowable material can be effected at least temporarily by the latent heat storage means, wherein the latent heat storage means is arranged within the receiving space or is formed as part of the wall wherein the latent heat storage means comprises a phase change material, wherein the phase change material absorbs energy during an endothermic change of state due to heating and releases energy in the form of heat during an exothermic change of state, wherein the phase change material is provided in such a quantity or mass that, with a receiving space filled at least 2/3 with flowable material tempered to a temperature above the melting point of the phase change material, the endothermic change of state of the phase change material is only partially effectable at an ambient temperature of 20°C, wherein the flowable material is a liquid, characterized in that the phase change material comprises at least salt constituents, wherein the melting temperature of the phase change material is between 36°C and 70°C, wherein the phase change material comprises sodium acetate trihydrate, wherein individual wall parts of the latent heat storage means are connected to one another by shape retaining elements or shape presetting elements, wherein a shape retaining element or a shape presetting element limits an expansion of the volume locally bounded by the walls.