The object of the present invention is a method for the treatment of hair, comprising the application to the hair of a composition comprising at least one organic monoacid and at least one cellulosic polymer, and a step of heating the hair at a temperature higher than 100° C. The method according to the invention makes it possible to obtain a solution for treatment of the hair in a way which is lasting and compatible with any type of past or future hair treatment and provides a volume reduction.
