Who: Clear with a medical professional to ensure that the sub can play with ice. For example, someone with Reynaud's syndrome will need to miss out on this kind of play.
What: Use only ice. Never use dry ice. The ice you use does not need to be super cold. Colder ice is sharper and therefore dangerous. If it clings to your skin, it's too cold. If it "weeps" where your fingers touch it, then it is probably the right amount of cold.
When: If you have never worked with ice, then your first ice play session should be really short. Get familiar with the sensations. A rule of thumb is no longer than a few minutes (<3 to be safe) if applied in the body.
Where: Ice can be used topically (on the skin), on or inside the genitals if proper care is taken. Light touches are all you need.
How: Quick, light touches. Move it until it melts. I'll answer Why (why people enjoy using ice) in the section below. :-)
Ice effectively sensitizes the skin with minimal amount in very little time. When rubbed on nipples, the area becomes numb and stiffens nicely for nipple clamp application.
A thin piece of ice inserted into the anus can intensify a man's orgasm when he ejaculates. This may not be true for every man. If you do test this method, remember to keep the contact with the skin light and quick. Careful that no cuts occur -- cuts can be very dangerous!
Best used with a blindfold, the submissive does not know what's coming! Ice can be used on the neck, inner thighs, bottom, over genitals, on hands and feet... Just keep it moving until it melts. This will often get the sub guessing, moving, moaning, groaning, even shrieking. :-)
Signs to Stop
Frost-nip* occurs when one feels numbness, pain, and decreased blood flow in the affected area. Apply heat to remedy.
Frostbite* is serious and occurs when ice has been applied too cold for too long. While frost-nip guarantees the tissue can revive, frostbite indicates tissue death. With no blood flow, the skin turns gray and feels very waxy. Although doubtful in occurrence during BDSM play, quickly use warm hands and underarms to warm up the nipped area.
Hypothermia occurs when ice has been inside the body too long. Even five minutes can be too long and can endanger the person's internal organs and temperature regulation system.
*In both cases (frost-nip and frostbite), do not apply hot wax or hot water to the area as the Rx prescription.