Let’s be honest. That sleek, bouncy blowout feels like pure magic until you start noticing the split ends, breakage, and that crispy sound when you run your fingers through your once-silky strands.

A woman has gone viral for a seemingly bizarre reason: blow-drying her hair. But the reason she blow-dried it has sparked a major online debate, and given her video a jaw-dropping 18 million views.

There is a lot of conflicting advice about “the best” way to take care of your hair—especially when it comes to the method of drying it. Some people will tell you that the only healthy option is to ...