A compress is a very basic form of treatment which entails the folding of a piece of material, bandage or small towel, into a pad by wetting it and applying it to the areas to be treated.

HOT : Hot compresses are used to treat old injuries, muscle pain, rheumatic pain, menstrual cramps, boils, and toothache.

COLD: Cold compresses are used for new sprains, bruising, swelling and inflammation, fever and headaches.

I think your question is as simple as you think, you could go on to explain how to make a hot and cold compress as well as what oils you would use for your choice of application.

Cheers.