The building blocks of English

Affixes

cryo-

Involving or producing cold.

Greek kruos, frost.

The usual adjective relating to very low temperatures is cryogenic, as in cryogenic freezing, in which tissues or foodstuffs are plunged into liquid nitrogen to preserve them; a cryostat maintains materials at a predefined low temperature; cryogenics is the study of materials at very low temperatures; cryosurgery uses intense cold to free and kill unwanted tissue; the cryosphere is that part of the planet that experiences persistent low temperatures, say at the poles or at high altitudes.