Cryotherapy is the use of liquid nitrogen, at a temperature of minus 196 degrees Celsius, to remove or ‘freeze’ small skin lesions that may be cancerous, such as basal cell or squamous cell carcinomas. Cryotherapy is a safe and reliable dermatological procedure, and has the advantage of being inexpensive compared to many other measures. Follow-up with the dermatologist is mandatory, as the cryotherapy as a keratoses-removal method sometimes requires more than one treatment. During the procedure, the nitrogen is applied directly to the skin lesion. Cryotherapy may sting or be a little uncomfortable during application and for a short period after the procedure. Immediate swelling and redness may occur. These effects can be treated with a topical steroid on a single occasion after freezing. Aspirin may also reduce the inflammation and discomfort.