A form of temperature play, though not always strictly BDSM; it is also a form of foreplay when practiced to a less extreme degree.
Common depictions involves running pieces of ice across a person's exposed skin, or French kissing while passing an ice cube.
In more extreme cases, in which a BDSM tag would suffice, ice can also be used as an insertable. This is either for the vagina, anus, and occasionally for the male urethra.
Ice play can be a risky practice, and as such, it can be considered a form of edgeplay; there are injury risks related to frostbite, hypothermia, and skin laceration.