Updated project metadata. We have carried out proteomic studies to identify the thermo-unstable proteome fraction in fission yeast. We have performed biochemical separation of pellet fractions by centrifugation of whole cell extracts from wild-type cultures grown at different temperatures, and performed untagged liquid chromatography coupled to tandem MS (LC-MS/MS) of biological triplicates. We demonstrate that formation of protein aggregates during heat shock is a chaperone-mediated adaptation strategy which occurs with thermo-unstable endogenous proteins as well.