The temperature at which you should turn on the heat in your home depends on several factors, including personal preference, age, and health. The World Health Organization recommends that regular people keep their homes at 64.4 degrees Fahrenheit or higher, while for those who are young or old (or who have an illness), it recommends a minimum indoor temperature of 69.8 degrees Fahrenheit. The Department of Energy suggests turning on the heat when the outside temperature falls below 68 degrees Fahrenheit to save on energy bills. However, these are just general guidelines, and the decision of when to turn on the heat is ultimately up to you. Some people prefer to wait until the temperature drops below 50 degrees Fahrenheit, while others turn on the heat as soon as they feel cold. Its important to note that if you have children, seniors, or people who are sick, you may need to set the temperature higher to keep them comfortable. Ultimately, the best temperature to turn on the heat is the one that makes you feel comfortable and safe.