Sometimes humans get fleas in their hair and on the scalp because fleas like to use hair as a way to attach themselves to the body of their host, and also because they use it as a place to hide and avoid detection.
Fleas cannot swim and easily drown in water, so an easy way to get fleas out of your hair is to take a bath and submerge your head underwater.
The fleas should quickly drown and you will see them float on top of the water. You can also take a hot shower if you prefer, and thoroughly wash your hair and scalp with a shampoo, which should do the trick as well.
Fleas can bite humans and live on them for a short period of time, but it is fairly easy for us to get rid of the fleas because there are not many natural places on the human body for fleas to attach and hide, unlike cats and dogs.