Cloud-point curves for the poly(ethylene glycol)/water system have been presented by Bae et al. (1991) and by Saraiva et al. (1993). In both cases, the data have been measured using a similar thermooptical analysis by microscopy (TOAM) apparatus. A systematic difference of 2-3 degrees C was found between the two sets of data for solutions of poly(ethylene glycol) with weight average molecular weight within the same order of magnitude. In a recent Letter, Pfohl et al. (1995) claim that this difference can be partially explained by the existence of temperature gradients in the hot-stage, which have not been taken in consideration by Saraiva et al. (1993). The purpose of this letter is twofold : 1) to demonstrate that the explanation given by Pfohl et al. (1995) for the difference between the sets of data is not fully justified and 2) to point out the advantages and disadvantages of the two configurations of the microscope hot-stage : the one proposed by Bae et al. (1991) and Pfohl et al. (1995) where copper-blocks are used to reduce the effect of the temperature gradients in the heating device, and the one where the copper-blocks are excluded.