This dataset contains raw data of respiration, survival and thermal sensitivity of respiration and survival of cold and warm acclimated amphipods used for analyses and figures in the research described in the Journal of Thermal Biology: It's about time: Linkages between heat tolerance, thermal acclimation and metabolic rate at different temporal scales in the freshwater amphipod Gammarus fossarum Koch, 1836. (2018) by Semsar-kazerouni and Verberk. In this paper, we examined the effect of temperature acclimation on heat tolerance and metabolism in the aquatic ectotherm Gammarus fossarum. Details about the experimental procedures are given in the Materials and Methods section of the paper. We have also included the R scripts for data analyses in this dataset. A brief description of the data files and column descriptions can be found below.