Body temperature 38.9. is it consider as high fever?

Medium / Moderate: A temperature of 101-102 f can be called a medium fever or moderate fever, if one separates fevers into low, moderate, and high. Depending on what symptoms are happening, how long they've been occurring, what underlying problems a person has, etc..., one can decide when to see a doctor. That means a fever of 102 in one person may be very serious, while in another person may be not serious.

Fever: Yes, a body temperature of 38.9 degrees celsius is considered a low-grade fever.