consult your doctors, but in my experience 37.5 is barely a fever, 38.5 is medium. 39 can be fought through but if you see 40 you shouldn’t risk it and just seek help. depending on your general health it doesn’t hurt to be safe and seek help even with 39.
for people who use normal human measurements:
100.4 is ~37.8,
103 is 39.4,
106 mentioned in another comment is 41.1
consult your doctors, but in my experience 37.5 is barely a fever, 38.5 is medium. 39 can be fought through but if you see 40 you shouldn’t risk it and just seek help. depending on your general health it doesn’t hurt to be safe and seek help even with 39.