A transformer assembly includes a housing, a core within an interior of the housing, and at least one winding positioned around the core. The at least one winding and the core are mounted to the housing with potting material. At least a portion of a fluid circuit is defined within at least one wall of the housing. The at least the portion of the fluid circuit is defined through an opening in the at least one wall of the housing in fluid communication with the interior of the housing. A transformer assembly includes a housing, a core within an interior of the housing, at least one winding positioned around the core, and a fluid circuit defined at least partially within at least one wall of the housing being configured such that heat is transferred to the fluid from at least one of the core and the at least one winding.