A membrane module comprising an outer casing having an interior region, a plurality of hollow fiber membranes extending through at least a portion of the interior region, and having exterior surfaces and inner hollow regions, where the inner hollow regions are configured to provide flow paths for a distillate fluid. The membrane module further comprises an opening extending through the outer casing for providing a feed solution to the interior region adjacent the exterior surfaces of the plurality of hollow fiber membranes, where the feed solution provided to the opening has an elevated temperature that is greater than an atmospheric-pressure boiling temperature of the feed solution, and an elevated pressure at which an effective boiling temperature of the feed solution is greater than the elevated temperature.