Eric Charbonneau / WireImage 1 / 16
Eric Charbonneau / WireImage 1 / 16

Baby, it's cold outside!

Despite the chilly temps, Jennifer Aniston and Justin Theroux kept things hot in Colorado for the first week of 2012! A source tells Us Weekly the duo vacationed in a 13,300 square foot private residence in the Mountain Village outside the town of Telluride -- where they were first spotted Dec. 31.

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"They had a group of friends [that left] Monday," the source tells Us. "Justin and Jen [stayed] until Thursday. They had a ski instructor every day."

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"[Jennifer] gets up [and] goes skiing," adds the source. "Pretty much [she's] camped out at the house, keeping a low profile."

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Another source tells Us that Aniston, 42, and pal Chelsea Handler took a ski lesson together.