Is my Dolphin sensitive to hot or cold water?
Absolutely, the colder the water, the less efficient the Dolphin robot will be.
Water that is too warm and badly calibrated and your pool will contain algae that could clog the filters and limit the adherence of your Dolphin.
As stated in the warranty document, the robot should only be used in water temperatures 43°F - 95°F (6°C - 35°C). (below 15°C / 59°F climbing performance may be affected)