Now, I don't want to be the typical bastard
scientific-minded
persnickety dick. But maybe I am one, even if I don't want to. This means that I will point out some things.
The pre-Big Bang Universe (which is in fact a lot of speculation) was neither hot or cold, since temperature is defined in ways that involve mean particle energy, and in illo tempore there were no particles.
You don't actually use heat to make the inside of the refrigerator cold. A fridge is a heat pump that transfers heat from a place to another, by means of a compressible fluid: in the process entropy increases (as always, as always ...) and you get some extra waste heat.
Of course, the Universe is not a refrigerator, because where would it dump the heat ?
And why would the freezing point be significant at all ? Even frozen things have thermal capacity.
Cold, per se, does not exist, and it has no place in physics. The cold is not trying to break into you. As you appropriately say, it is just your heat (or the agitation of the molecules that make up your body) communicating itself to whatever happens to be around you.
Lastly, the lizard is a singularly bizarre example, since it is a cold-blooded animal ... but you must have had reasons for choosing one of our reptilian buddies.
If you really want to feel grandly unified, remember that it all boils down to statistical mechanics, which in turn boils down to entropy. And to the eventual heat death of the Universe, if you can stand the thought.
Nonetheless:
I hug you. Heck, I lived in Pittsburgh, and before I bought longjohns, I nearly lost my butt to frostbite. You deserve a hug. And remember, wear two pairs of socks, thin cotton ones on your feet and thick woolen ones over them.
there, I had told you that this was going to be a party pooper WU, hadn't I ?