Abstract: In a thermally developable light-sensitive material comprising a support having therein or thereon at least one layer containing at least (a) an organic silver salt, (b) a light-sensitive silver halide or a component capable of forming a light-sensitive silver halide and (c) a reducing agent, the improvement wherein at least one layer provided on the support comprises, or the support is impregnated with, (d) at least one member selected from the group consisting of rosin of an acid value more than about 100, one or more diterpene acids or a mixture thereof in an amount sufficient to decrease heat fogging and to improve the storability of light-sensitive materials.