The present disclosure is related to nested cooling and heating systems. The cooling system includes an outer cooling assembly with an inner cooling assembly inserted within the outer cooling system. The inner cooling assembly includes thermoelectric coolers, and the outer cooling assembly may thermoelectric or vapor compression driven. Additional intermediate cooling assemblies may be nested together with the inner and outer cooling assemblies to increase the cooling effect in the innermost cooling assembly. Similarly, the heating system uses nested thermoelectric heating assemblies, and hot temperatures can be increased by adding intermediate nested heating assemblies. Intermediate and/or inner assemblies may be removed from the outer assembly to allow for easy transport.