Okay, I just spoke to my boss who has a PhD in Physics. Don't ask.

Using Charles Law which states that under conditions of constant pressure and quantity,
there is a direct relationship between the volume and absolute temperature for an ideal
gas.

Supposing a 20C or 36F degree temp range.
273 (absolute temp, zero scale) + 20 = 293.
20/293 = .068
That means there is 6% change.

Plastic soda bottles can certainly handle 6% expansion and contraction.

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Tailgunner
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