When you are trying to decide which TOG rating is best for your little one, pay attention to the temperature of the room they are in, rather than the season. A 1.0 TOG rating is ideal if your baby is in an environment where the temperature is between 75 and 81°F (or between 24 and 27 °C). If you find your home is within this temperature range during the winter than a 1.0 TOG sleep bag will be suitable. If your home is colder than this during the winter, opt for a sleep bag with a higher TOG rating.