The answer to 'shut-off valve frozen' is that a frozen shut-off valve is a common plumbing issue, often caused by cold temperatures or a lack of insulation. Symptoms include difficulty turning the valve or water not flowing when the valve is opened. The solution may involve carefully thawing the valve, insulating the pipes, or replacing the valve if it is severely damaged.
If the valve is frozen, it's best to try to thaw it gradually using a space heater, heat lamp, or warm towels. Avoid using open flames or excessive heat, as this can damage the valve. If the valve remains frozen or is difficult to turn, it's recommended to call a professional plumber who can safely assess and repair the issue.