Second Lowest Temperature

The penguin colony reports each night's temperature, and scientists want the second coldest night. 🐧

You get a list of temps — at least two, all different. Print the second lowest, in one pass, no sorting.

Example:

Input: temps = [-4, -12, 3, -9] Output: -9

-12 is the coldest night. Tracking the second-coldest alongside it, that turns out to be -9.