Described embodiments include an apparatus that includes an electrical interface and a processor. The processor is configured to receive, via the electrical interface, a temperature sensed by a temperature sensor at a distal end of an intrabody probe, to estimate a temperature of tissue of a subject, based on the sensed temperature and a parameter of an ablating current driven, by an ablation electrode at the distal end of the intrabody probe, into the tissue, and to generate an output in response to the estimated temperature. Other embodiments are also described.