A sealed, double walled water packet has an inner packet filled with potable water that has a porous outer surface layer containing absorbed water and an outer packet that encloses the inner packet and is connected to the inner layer. The inner packet (which may contain as little as a swallow of water) is connected to the outer packet (both of which can be made as envelopes with tearable sections or peel off corners) along one side or by a string so that the inner packet can be twirled or waved to cause rapid evaporation of water in the porous outer surface layer (which can include hydrogel) to thereby cool the potable water contained inside the inner packet before it is opened.