What Is the Rule of 200 in a Sauna? Temperature, Humidity and Löyly Explained

The rule communicates one useful idea: sauna temperature cannot be fully understood without considering humidity. Adding water to properly heated sauna stones can make the heat feel substantially more intense, even when the thermometer barely changes. However, the Rule of 200 is not a scientific safety standard, a medical recommendation or a formally recognized Finnish sauna rule. Two sauna environments that both total 200 can feel very different.







