So after reading over other blood colors and the benefits of other blood bases I wanted to create a species that used Coboglobin instead of Hemoglobin. Though based off of Jim2B presented of,
On this chart it shows that Coboglobin is most effective at 15 Celsius body temperature and a lower partial pressure than Hemoglobin, (Still not sure what that means yet, but meh.)
With that information my question is what kind of environment would produce the most effective use of having such a low internal body temperature and lower partial pressure. (Assuming that it would be a warm bloodied creature.)