Zeeman interferometry, based on the two-frequency Zeeman effect laser, can be used for simple, noncontact differential thermometry. The thermometry is differential in both space and time. Small (0.73 μℓ ) laser-heated volumes were monitored with a Zeeman interferometer. Heating rates varied over six orders of magnitude from 180 μK/s to 330 K/s. Temporal resolution was 10 μs. Measured temperatures and measured rates of heating were compared with theory for slowly and rapidly heated samples, respectively.