Why do I yawn excessively when physically cold

Factual Questions
1

Why do I yawn excessively when physically cold. The thermostat at work is set at 65 degrees (f). Once I start to feel cold (but not shivering) I start to yawn uncontrollably. I do not use opiates or other drugs - the most found reason on the internet.

Thanks for any insight.

2

Cold is tiring. Your body has to expend additional resources to keep your temperature elevated.