A reservoir for supplying a cooling fluid to a medical ablation probe includes a wall defining a chamber therein, an outlet fluid port and an inlet fluid port each in fluid communication with the chamber, cooling fluid disposed within the chamber, and a thermochromic material thermally coupled to the cooling fluid. The thermochromic material is configured to exhibit a first color when the cooling fluid is below a threshold temperature, and a second color when the cooling fluid is above the threshold temperature.
