Looking on the internet deeply has found these results:

wearing a hat on his head is the most popular phrase on the web.

wearing a hat in his head 10 results on the web	wearing a hat on his head 1437 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	11589415. Newborn Baby boy sleeping while wearing a hat on his head. ... to fully use his hands, painting his stunning nature watercolors wearing a hat on his head to which a binder clip with a brush is attached. Not your typical artist. In his place a little rabbit appeared wearing a hat on his head. When Andrew came near the rabbit, the rabbit smiled and winked at him, and then it ran into the �... Newborn Baby boy sleeping while wearing a hat on his head. Stock Photo Dog wearing a hat cone. Sable dog border collie wearing a hat on his head, portrait in winter. MR: NO; PR: NO. 0; 620; 0. Stock Images: Dog wearing a hat cone.

wearing a hat in his head

10 results on the web

wearing a hat on his head

1437 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

11589415. Newborn Baby boy sleeping while wearing a hat on his head.
... to fully use his hands, painting his stunning nature watercolors wearing a hat on his head to which a binder clip with a brush is attached. Not your typical artist.
In his place a little rabbit appeared wearing a hat on his head. When Andrew came near the rabbit, the rabbit smiled and winked at him, and then it ran into the �...
Newborn Baby boy sleeping while wearing a hat on his head. Stock Photo
Dog wearing a hat cone. Sable dog border collie wearing a hat on his head, portrait in winter. MR: NO; PR: NO. 0; 620; 0. Stock Images: Dog wearing a hat cone.