Cryotherapy is a treatment using very cold liquid nitrogen to"freeze off" skin lesions such as genital warts. 

The extremely low temperature destroys the abnormal cells, allowing  normal cells to grow in their place. This forms a scab and falls off naturally 12-14 days later.

Cryotherapy is well tolerated by patients and treatment lasts less than a minute. Some lesions may require a course of several treatments over a number of weeks.