6LiF enhanced dosemeters exposed to high fluences of thermal neutrons undergo irreversible radiation damage, preventing their subsequent utilisation. 6LiF depleted dosemeters do not show such an effect, but in mixed fields of high fluxes with thermal neutrons they do not provide a simple way of discriminating among the contributions of the field components. The responses to thermal neutrons and to gamma rays of some TL single crystals have been investigated. LiF:Mg,Cu,P and LiF:Cu2+ single crystals have shown a much higher sensitivity to thermal neutrons than to gamma rays. KMgF3, although promising for other dosimetry purposes, shows no useful features in such radiation fields.