WATCH: Trump Lets Jimmy Fallon Mess Up His Hair

Donald Trump had a "hair-raising" experience on "The Tonight Show" last night.

The Republican presidential nominee joined host Jimmy Fallon to discuss a wide variety of topics, including the 2016 campaign, his health and, yes, his hair.

Fallon noted that the next time he sees Trump, he could be the President of the United States, so he asked if he could do something "not presidential."

"Can I mess your hair up?" Fallon asked, to raucous applause and cheers from the audience.

Trump agreed! 

Watch the hilarious moment above.

Trump joined Maria Bartiromo this morning on Fox Business Network, where he was asked about the memorable moment.

He said the video proves "my hair is my hair" and should put to rest any theories to the contrary. 

Following his interview Thursday with Dr. Oz, where he discussed his health, Trump said he feels like he's 35 years old. 

"I don't think I'm 35, but I feel the same in terms of my health as if I'm 35," explaining the grueling schedule he has kept during the campaign and arguing that it's "much more vigorous" than Hillary Clinton's.