nutritive nutri-thermique thermo-reactive intensive nutrition masque by kerastase Masque : Deep Nutrition, an exclusive complex of nourishing agents operates in the most sensitised areas of the fibre offering intense nutrition to the hair. Heat activates the thermo-reactive formula, trapping the nourishing elements deep inside the hair fibre. The heat-activated formula creates a protective film all around the fibre to help prevent dryness. Thermic protection.