The ability to sense environmental temperatures and to avoid noxious heat or cold is crucial for the survival of all organisms. In mammals, sensory neurons from dorsal root and trigeminal ganglia convey thermal information from the skin, mouth and nose to the central nervous system. Recent evidence has established that thermoTRPs, a subset of the TRP superfamily of cation channels, act as primary temperature sensors in cold- and heat-sensitive neurons. The gating of these thermoTRPs exhibits strong temperature dependence, leading to steep changes in inward current upon heating or cooling. Moreover, several natural or synthetic compounds act as ligands of thermoTRPs, thereby creating sensations of cold or hot independent of actual changes in temperature. In this presentation, I will present our latest insights in how these channels detect and integrate thermal and chemical stimuli, and discuss the in vivo consequences of thermoTRP gating .