A hair treatment method comprising steps 1 to 5 to be performed in the following order: 1. a step of applying a first composition to hair, wherein the first composition is acidic and comprises one or more selected from the group consisting of glyoxylic acid, glyoxylic acid hydrates, glyoxylates, and glyoxyl amides； 2. a step of leaving the hair having the first composition applied thereto to stand； 3. a step of heating the hair with a high temperature heating device； 4. a step of applying a second composition to the hair, wherein the second composition comprises an oxidizing agent, has a pH of 0.5 or more and less than 8.0, and has a content of a dye component of less than 0.4% by mass； and 5. a step of leaving the hair having the second composition applied thereto to stand.
