What effect does an increase in temperature have on hemoglobin's ability to bind oxygen?

Increase in temperature weakens the chemical bond that exist between oxygen and hemoglobin, this cause an increase in dissociation level of the two. The reverse is also true; a decrease in temperature reduces the dissociation between the oxygen and the hemoglobin particles. The temperature of the body must be kept fairly constant in order to achieve the right level of association between the oxygen and the hemoglobin particles.