Liver HSP70 in juvenile salmon exposed to diel cycles: (A) 16–21°C only; or multi-day thermal stress (closed symbols; 60–120 h) of (B) 18–27°C; (C) 20–27°C; (D) 22–27°C. Data are presented as mean ± SEM (n = 5–9). Pre-thermal stress sampling (open symbols; t = 12 & 24 h) assessed the effect of ‘trial’ and was not included in the analysis. Letters indicate significant differences among treatments (P < 0.05) within sampling time points.