there is disclosed an improved heat sink composition and a method for preparing said composition to protect thermolabile goods from degradation or destruction from high temperatures . a representative composition includes sodium sulfate , sodium sulfate decahydrate and fumed silcon dioxide , a hydrophilic suspension agent which maintains the excess anhydrous sodium sulfate in uniform suspension when the composition is in a liquid state . in a preferred embodiment , the salt prior to use is dissolved in water , and driven to saturation , the hydrophilic agent is added , and the suspension driven to an over saturated state by the additional of from 1 to 30 % anhydrous salt . the composition is then sealed in a plastic container of the desired shape to form an improved heat sink . the goods to be protected are packaged with the heat sink , whose salt hydrate has a melting point about 3 ° c . to about 5 ° c . lower than the thermosensitive temperature of the goods to protect them when the temperature of the environment exceeds the temperature of the goods . in the preferred embodiment , the goods and heat sink are surrounded with a layer of insulation which is adjacent to the outside container , which may be made of cardboard , paper , plastic and / or wood .