Icilin cooling molecule. Computer model of a molecule of the cooling agent icilin. Atoms are represented as spheres and are colour-coded: carbon (blue), hydrogen (white), oxygen (green) and nitrogen (pink). Icilin is related to methanol. It produces a cool sensation when applied to tissues by activating the TRPM8 ion channel in nerve cells. Icilin has been shown to have analgesic (painkilling) effects as the cooling sensation suppresses other sensory inputs.