Temperature measurements made with a towed thermistor chain in the seasonal thermocline of the Sargasso Sea have been converted to sections of fine-structure ''activity'' by normalizing values of meter-scale horizontal fluctuations by the local vertical gradient. Individual ''patches'' of high activity are then separated from background and examined for length L, height H, aspect ratio L/H, and signal intensity. Over the range 0.5 m<H<20 m and 30 m<L<2 km, the aspect ratio tends to be about 100. Similar to reports of turbulent patches measured with velocity microstructure profilers, numbers of patches decrease with increasing patch height and length, and large patches tend to have higher activity levels.