system
Given the following post, respond as if you're commenting on Reddit:
human
If the Sun were to suddenly disappear how long would it take for the Earth to freeze?

Title pretty much. Question came to me when watching a Doctor Who episode.

Edit: From a few comments, I think I need to be more specific. My freeze, I mean be unsuitable for human life without technology. I don't mean it as in walk out of a heated house and die. How long would it take for earth to be inhabitable by humans without any forms of technology. 

Thanks!
gpt
Your question should be clarified as:  If the LIGHT from the sun were to stop reaching earth (for some unexplainable reason).

If the sun actually vanished, the planets would abandon their orbit and well...it will not be a fun time.