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A 9 month old baby is brought in with this problem, first noted a few hours prior.

Hair tourniquet

By James Heilman, MD [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], from Wikimedia Commons

What is your best course of action?