If the apparent visual magnitude of the Sun is -26.5 and that of the full moon is -12.5, what is the light intensity ratio of sunlight to moonlight received at Earth on the day of the full moon?
Symptoms of a cold sore can include: 1  a tingling sensation, redness and swelling around the lip before the cold sore develops. 2  small, fluid-filled blisters which break open and develop a yellow crust (scab). The scab usually falls off around seven days later.
They usually appear on the lip, though, and they can be painful. If you have one on your face, it may not be as painful as one on the lip. The cheek doesnât stretch and move as much. In this article, we will talk about the virus, and how it can causes cold sores to appear on the cheek.