Liquid nitrogen freeze spray

Liquid Nitrogen boils at about minus 196 degrees Celsius, or just 77 degrees Kelvin (minus 320 degrees in the old Fahrenheit scale)

Either way it is very very cold.

In dermatology, liquid nitrogen is used as a spray onto the skin in order to kill unwanted surface cells

Solar keratoses (=actinic keratoses) (="SK") are sometimes called skin cancers, but they are not quite that. Perhaps one in a thousand will turn into a skin cancer eventually. But they are flakey unsightly thickenings of the epidermis typically found on the long-exposed skin of older white-skinned people, and they are "pre-cancerous"

Squirting a bit of liquid nitrogen on a solar keratosis feels a little sore, and feels a bit more sore as it thaws, but the liquid nitrogen kills the surface SK cells. the treated areas swells a little, and might form a blister, but there's no blood and no break in the dermis so a dressing isn't necessary. The SK falls of after a few days or a week, and fresh new healthy skin will grow beneath.

Sometimes the treatment will leave a white/de-pigmented spot. For this reason it is better to under treat than over treat, and treat again if necessary.

Liquid nitrogen is a great treatment for warts

Liquid nitrogen is a great treatment for these too

Liquid nitrogen is NO GOOD for skin tags. Hyfrecation or laser is much better.