Slow cookers have different temperature ranges, and the "high" setting can vary depending on the brand and model of the slow cooker. However, most slow cookers reach a temperature range of around 175°F to 215°F, with the low and high settings peaking at 215ºF. The low setting cycles on and off that temperature more frequently, while the high setting will cook the food in a shorter time than the low setting. The Crock-Pot brand, for example, reaches the simmer point and stabilizes on both "High" and "Low" at about 209°F. According to one source, slow cookers all reach the same temperature range, which is around 104-112 degrees Celsius.

Its important to note that the difference between the "high" and "low" settings is not really in the temperature, but in the speed that the cooker comes up to its "simmering" temperature. Therefore, its recommended to follow the cooking times in a recipe rather than relying solely on the temperature setting.

To ensure that your slow cooker is working efficiently, ensure the cooking liquids temperature is 185°F. If it runs too high, you can overcook meat (depending on the cut). Too low, and your food will be unsafe to eat. The temperature danger zone of optimal growth for spoilage microorganisms is about 40 to 140°F, primarily if held for over 3 to 4 hours at this range.