Changes in the activity of Na+/K+-ATPase and content of membrane lipids (phospholipids) in the gills and hepatopancreas of the blue mussel Mytilus edulis L. have been studied during a sharp temperature increase under aquarian managed conditions. The most pronounced changes were recorded in mollusk gills. A correlation of changes in the activity of membrane-bound Na+/K+-ATPase and phospholipid content (mainly phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, and lysophosphatidylcholine) was revealed; this correlation evidences their mutual involvement in compensation for the temperature effect to help mussels adapt to sharp temperature changes.