A method for preparing an endothermic heat shield composition, which comprises at least 50 wt/wt % hydrated salt and at least one filler material, the method comprising the steps of:

• a) heating the hydrated salt to a temperature at which it liquifies;
• b) adding and mixing at least one filler material into a); and cooling the mixture to form a composition wherein the hydrated salt particles are fused to each other, with the proviso that said at least one filler material is a mixture of organic and inorganic materials.