Why do I yawn when it's cold?

I know it's a weird aversion.Why do I yawn when it's cold?
Although there are a LOT of theories why folks yawn, none of them has ever be proven. Due to problems researching something that seamingly occurs variable.
Some of the theories are:
1. An indication of tiredness, stress, over-work, or boredom.
2. An action indicating psychological decompression after a state of illustrious alert.
3. A means of expressing powerful emotion like anger, apathy, remorse or boredom.
4. A regulation of body temperature
5. It's a purely chemical aversion from the brain. These chemicals include serotonin, dopamine, glutamic acid and nitric oxide. As more of these compounds are activate in the brain, the frequency of yawning increases.
Why yawning could be contagious:
The proximate wreak for contagious yawning may lie beside mirror neurons, i.e. neurons in the frontal cortex of sure vertebrates, which upon being exposed to a stimulus from conspecific (same species) and occasionally interspecific organisms, activate the same regions contained by the brain[4]. Mirror neurons have be proposed as a driving force for imitation which lies at the root of much human erudition, e.g. language purchase. Yawning may be an offshoot of the same imitative fad.
Please bear within mind that all of this are THEORIES and not PROVEN cases.
Are you sure that it is when you get the impression cold?
When there is insufficent oxygen supply, humans yawn.
The cold nouns makes it somewhat harder for you to breathe...