The answer to 'why is my faucet frozen' is that the water supply line leading to the faucet has likely frozen, preventing water flow. This is a common problem during cold weather, especially in homes with inadequate insulation or exposed plumbing. Symptoms may include a faucet that won't turn on or that only drips slowly.
To fix a frozen faucet, you'll need to thaw the supply line. This can be done by applying gentle heat to the frozen area, such as with a space heater, heat lamp, or hair dryer. Avoid using open flames, which can damage the pipes. If the line is severely frozen or difficult to access, it's best to call a professional plumber who can safely and effectively thaw the pipes.