A temperature gradient is required for any type of heat flow process. In a dynamic calorimeter, temperature gradients exist in the entire calorimetric system during the measurement of temperature differences or heat flow. Most organic materials are of relatively low thermal conductivity in comparison to metallic and inorganic materials. Therefore large temperature gradients are expected to exist in organic materials during the measurement. The magnitude of the temperature gradient can be estiamted through a simple modeling procedure. The results of experimentally determined temperature gradients during the cure of an epoxy resin in a differential scanning calorimeter are presented to confirm the expected magnitude of temperature non-uniformity.