Chances are, you had a mood ring as a kid. Yep. The one that would magically change its color depending on your mood. Or rather the temperature of your finger that correlates to it.
Well, judging by all these photos and videos ladies were uploading on Instagram lately, mood rings have some serious competition.
Say hello to Mood Nail Polish. And yes, it's an actual thing. Once applied, this nail polish changes color depending on your body temperature.