Is it possible to transplant body hair from the chest, arms, legs, etc on to the head?

Thank you for your question. The simple answer to this is that yes hair can be transplanted from anywhere. But the hair cycle is different in the scalp compared to elsewhere. Also, due to the hair density on the scalp donor site, the scars are better hidden from the hair harvest. even with single unit extraction,this will leave a small scar which on the arm or chest may look more like a pimple and is unlikely to be hidden by adjacent hair. Taking a strip of skin will result in a scar which again will be obvious. 
If you have a sufficient amount of hair on the back of your head, this would be the preferred donor site. 
I hope this is helpful for you 
BW
Rohit Seth
Plastic, reconstructive, aesthetic and hair transplant surgery

Yes, technically it can be done. However, it is an option of last resort and will not give you hair that matches normal hair of the scalp. It will be shorter and basically behave exactly as it does from where you take it. Also, there will be scarring present from where you take the grafts that can be difficult to hide.