pockets 28 two working agent pouches can be recognized by small outward bulges 30 at the lower end of the evaporator region 22 to trigger the cooling function pressure is exerted on these working agent pouches until their sealing seams burst due to the peel effect of the film and the degassed water enclosed in them is allowed to flow out into the structural material the subsequent homogeneous distribution of the water in the evaporator nonwoven progresses in accordance with the invention also in this embodiment the cooling operation can be achieved with the opening of just one pouch the second working agent pouch can be activated at any later time of course each working agent pouch contains only a partial amount of the amount of water that can be maximally adsorbed by the zeolite filling in order to make available sufficient adsorption capacity for the second cooling operation the waste heat from zeolite region 23 is given up to the ambient air due to the positioning at the top the warm moist air cannot heat the evaporator region 22 fig9 shows a horizontal section through the zeolite region 23 along line ff in fig8 inner and outer multilayer films 31 and 32 are sealed so that they form four pockets 28 with zeolite filling 33 that are approximately of the same size along the three sealing seams 34 the four pockets are movable against each other they thus allow the cooling element easily to lie against the beer keg and to be secured there if the structural material is also divided in the evaporator region in.