A fluid reservoir includes a housing having a body, a leading end, and a trailing end enclosing a fluid chamber storing fluid therein, sealed inflow and outflow ports disposed at the leading end of the housing, and a heat exchanger disposed at the trailing end of the housing. An ultrasonic surgical instrument includes a housing defining a barrel portion and a fixed handle portion extending from the barrel portion, an ultrasonic transducer received at least partially within the barrel portion of the housing, a waveguide operably coupled to the ultrasonic transducer and extending distally from the housing to a blade configured to treat tissue with ultrasonic energy produced by the ultrasonic transducer and transmitted along the waveguide, and a fluid management system disposed within the housing. The fluid reservoir is configured for releasable engagement with the fixed handle portion to facilitate cooling of the blade with fluid.