Adam Clarke on Proverbs 25:13

As the cold of snow - That snow was frequent in Judea, is well known; and that in the East they have snow-houses - places dug under ground, where they lay up snow for summer use - is also a fact. By means of the mass of snow desposited in them the icy temperature is kept up, so that the snow is easily preserved. The common method of cooling their wine, which is as easy as it is effectual, is by dipping a cloth in water, wrapping it round the bottle, and then hanging the bottle in the heat of the sun. The strong evaporation carries off the caloric from the wine, and the repetition of the wet cloth in the same exposure, makes the wine almost as cold as ice.

How agreeable this must be in a burning climate, may be easily conceived. Perhaps it is this to which the wise man refers; for it is a fact that they could have no snow in harvest unless such as had been preserved as mentioned above; but this could be only in a few places, and within the reach of a very few persons. But cooling their liquors by the simple mode of evaporation already explained, was within the reach even of the laborers in the harvest field. I think the text favors this supposition; for כצנת שלג ketsinnerth sheleg, need not be referred to snow itself procuring cold, but to a coldness like that of snow, procured by evaporation. If this interpretation be allowed, all difficulty will be removed.