From the energy perspective, you need a certain amount to increase the temperature of the snow form initial temperature to over 0°C, and another amount to overcome the latent heat (heat of transformation) from solid ice to liquid water.
The latter, the heat of transformation from solid to liquid, is quite large and has been used for making ice cream whitout a refrigerator: Melting ice cubes in a large bowl with the help of salt was used as a cooling agent to freeze the ingedients contained in a smaller bowl placed inside the larger one.