Abstract: An insulated modular cooler comprising in one embodiment a plurality of tubular housing sections and a plurality of tubular hollow-walled insert housings containing a refrigerant in the hollow walls of the insert housings. The tubular housing sections can be secured end to end to form an elongated tubular body into which the tubular insert housings are slidably received. The cooler further comprises a top end cap adapted to engage the top of the tubular cooler body as well as the top of each individual cooler housing sections, and a lower end cap adapted to engage the bottom of the tubular body as well as the bottom of each individual cooler housing section. Other embodiments are described in which the inserts are integral with the housing sections, in which several inserts are slidably receivable in a single housing section and in which a single insert is slidably received in each modular housing section.