A mixture having a freezing point of up to 50°C, formed by mixing: (a) one molar equivalent of a salt of formula I (M n+)(X -) n or a hydrate thereof; wherein M represents one or more metallic elements selected form the group consisting of Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, In, Sn, TI, Pb, Cd, Hg and Y, X - is one or more monovalent anions selected from the group consisting of halide, nitrate and acetate and n represents 2 or 3; and (b) from one to eight molar equivalents of a complexing agent wherein the complexing agent consists of one or more compounds of formula II and/or formula III, HO-A-OH III wherein R 1 represents H, C 1-4 alkyl (which latter group is optionally substituted by one or more F atoms), or N(R 2)R 3; R 2 and R 3 independently represent H or C 1-4 alkyl (which latter group is optionally substituted by one or more F atoms); A represents C 2-10 alkylene optionally (i) substituted by one or more substituents selected form F, OH, SH and N(R 4)R 5, and/or (ii) interrupted by one or more groups selected from O, S and NR 6; and R 4 to R 6 independently represent H or C 1-4 alkyl (which latter group is optionally substituted by one or more substituents selected from F and OH); provided that the compound of formula III does not contain any C-atoms that are bonded to more than one atom selected from the group O, S and N which mixing is performed in the absence of extraneous solvent. (a) one molar equivalent of a salt of formula I (M n+)(X -) n or a hydrate thereof; wherein M represents one or more metallic elements selected form the group consisting of Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, In, Sn, TI, Pb, Cd, Hg and Y, X - is one or more monovalent anions selected from the group consisting of halide, nitrate and acetate and n represents 2 or 3; and M represents one or more metallic elements selected form the group consisting of Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, In, Sn, TI, Pb, Cd, Hg and Y, X - is one or more monovalent anions selected from the group consisting of halide, nitrate and acetate and n represents 2 or 3; and (b) from one to eight molar equivalents of a complexing agent wherein the complexing agent consists of one or more compounds of formula II and/or formula III, HO-A-OH III wherein R 1 represents H, C 1-4 alkyl (which latter group is optionally substituted by one or more F atoms), or N(R 2)R 3; R 2 and R 3 independently represent H or C 1-4 alkyl (which latter group is optionally substituted by one or more F atoms); A represents C 2-10 alkylene optionally (i) substituted by one or more substituents selected form F, OH, SH and N(R 4)R 5, and/or (ii) interrupted by one or more groups selected from O, S and NR 6; and R 4 to R 6 independently represent H or C 1-4 alkyl (which latter group is optionally substituted by one or more substituents selected from F and OH); provided that the compound of formula III does not contain any C-atoms that are bonded to more than one atom selected from the group O, S and N which mixing is performed in the absence of extraneous solvent. R 1 represents H, C 1-4 alkyl (which latter group is optionally substituted by one or more F atoms), or N(R 2)R 3; R 2 and R 3 independently represent H or C 1-4 alkyl (which latter group is optionally substituted by one or more F atoms); A represents C 2-10 alkylene optionally (i) substituted by one or more substituents selected form F, OH, SH and N(R 4)R 5, and/or (ii) interrupted by one or more groups selected from O, S and NR 6; and R 4 to R 6 independently represent H or C 1-4 alkyl (which latter group is optionally substituted by one or more substituents selected from F and OH); (i) substituted by one or more substituents selected form F, OH, SH and N(R 4)R 5, and/or (ii) interrupted by one or more groups selected from O, S and NR 6; and R 4 to R 6 independently represent H or C 1-4 alkyl (which latter group is optionally substituted by one or more substituents selected from F and OH);