Extremes

noun

1. The greatest or utmost point, degree or condition.
2. Each of the things at opposite ends of a range or scale.

   "extremes of temperature"

3. A drastic expedient.

   "Some people go to extremes for attention on social media."

4. Either of the two numbers at the ends of a proportion, as 1 and 6 in 1:2=3:6.