In a very basic and simple way can you tell me the symptoms of smallpox?

Smallpox. Currently a disease not in existence in humans, but preserved in at least 2 labs. It produces fever, malaise and skin lesions which are like blisters, come out all in one crop, may be slightly umbilicated (have a little dent in center). They break down, may bleed, leave ulcers and if you survive, deep pitting scars.