Heated socks can stay warm for a couple of hours up to several hours. Most heated socks have different temperature settings for you to choose from and the setting you choose will be the deciding factor in how long your heated socks stay warm. If you choose the lowest heat setting, you may be able to keep your feet warm for an entire day of outdoor activity, perhaps even longer. Choosing the highest heat setting will deplete the battery faster which will result in fewer hours of warmth.