Process for treating keratin fibres with input of heat

A process for treating keratin fibres, the process comprising:

• applying a hair treatment composition to the keratin fibres, the hair treatment composition comprising at least one of fatty substances, surfactants, polymers with a glass transition temperature (Tg) ranging from about 40° C. to about 150° C., oxidation dye precursors, and direct dyes;
• inserting the keratin fibres into a device comprising two elements that are moveable relative to each other between an open position and a closed position, wherein, in the closed position, the two elements define a substantially leaktight closed space;
• moving the two elements into the closed position to confine the keratin fibres in the closed space;
• and
• heating the keratin fibres to a temperature ranging from about 40° C. to about 250° C. while the keratin fibres are confined in the closed space.

A kit comprising:

• a device comprising a heat source and two elements that are movable relative to each other between an open position and a closed position,
• wherein, in the closed position, the two elements define a substantially leaktight closed space;
• and
• a compartment containing a composition comprising at least one of fatty substances, surfactants, polymers with a glass transition temperature (Tg) ranging from about 40° C. to about 150° C., oxidation dye precursors, and direct dyes.

A device for treating keratin fibres comprising:

• a hear source;
• and
• two elements that are moveable relative to each other between an open position and a closed position,
• wherein, in the closed position, the two elements define a substantially leaktight closed space,
• wherein each of the two elements comprises a seal at least partly delimiting the closed space, wherein the seals of the elements are applied against each other in the closed position of the elements.