This record contains data generated from a laboratory-based study examining the persistence of warm water acclimation following cold water recovery in an iconic cold-water species, the Eastern brook trout. The data set includes Critical Thermal Tolerance (CTmax) measures of fish in treatment groups: control (15 degrees C throughout), 1, 3, 7, and 14 days in warm water exposure (22 degrees C) followed by a 2 week cold water (15 degrees C) recovery. Physiological indices were also measured at both warm water treatment and post recovery. Growth and CTmax was recorded after two weeks of recovery temperature for control and all warm treatment groups, and after 30 and 42 days of cold water recovery for control and 14 day warm water treatment group.