Lemon is one of my favorite scents. I love it. In my Scentsy warmer, one of the scents I burn most often is called Coconut Lemongrass, and I also love cutting up lemons - it leaves my hands smelling pleasantly lemony for a long time afterward. Amazzzingg. :)
Anyway, lemon oil must be used carefully because too much can cause skin irritation and sensitivity.
Lemon oil helps with circulation and regulation of blood pressure, temperature, heart rate, etc. It helps with arthritis and rheumatism.
It can also be used as an astringent, antitoxin, and insecticide (which means it is put to good use in fly repellant).
It promotes sweating, which helps to rid the body of toxins. It can be diluted and applied around wounds because of its antiseptic properties, to clean the wounds and help them to begin healing. Lemon oil also relieves muscle spasms. It reduces temperature and fever, and it produces white blood cells, which help to fight infections.
It also helps stop external bleeding and stomach bloating.
Lemon and Chamomile are supposed to be good for maintaining immunity against infectious illnesses and viruses.
You should never leave lemon oil in the sun because it is phototoxic, and you should also never leave the lid off of it for extended periods of time because citrus oils oxidize faster than others and can cause skin irritation and sensitivity.
As usual, all of the information in this post is from Essential Oils for Horses by Carole Faith. :)