Linear solvation energy relationships and solvatochromic parameters have been used to develop an improved relationship for the partial molar heats of transfer of an infinitely dilute solute in nonionic solutions which appears to be accurate to +/-4% for the database tested. This result has been coupled with a thermodynamic cycle in order to develop a corresponding correlation for the partial molar excess enthalpy at infinite dilution, h(E infinity). However, because this result represents the difference of large : numbers, the accuracy of prediction of h(E infinity) is only accurate to about +/-28%. The correlation presented provides the insight for understanding, on a chemical and physical basis, the temperature effect on the phase equilibria of dilute solutions.