TMDSC data have been employed to observe the effect of NaCl on the inverse temperature transition of the model elastin-like polymer (GVGVP)(251). NaCl causes a decrease in T-t and an increase in Delta H. The increase in enthalpy appears both in the enthalpy related with the folding of the polymer and in the contribution associated with disruption of the structured water of hydrophobic hydration. It has been suggested that the presence of NaCl may cause a better formation of water structures surrounding the apolar polymer chains.