Can I add RGB?

No! Not my annulus!

mmm... annulus

But the goal here isn't to maximize cooling, you still want the tea to be hot, just drinkably hot rather than dangerously.

1. Use a metal straw to improve heat conduction.

While metal is a better conductor of heat, when looking at the effective rate of cooling you need to take the wall thickness into account. I think a plastic straw with it's micrometer thin walls is unbeatable.

Edit: I have trouble finding information on wall thickness of drinking straws, it one source says they are 130-250 μm thick. That is thicker than I expected.

This man HVACs

Hear me out, what if we added racing stripes to the straw?

its also very low volume so i think it will be fine for the job

Well that's why they invented crazy straws after all!

But can you play snake on your kettle

I bought a kettle with a temperature selector. I have one degree of precision. Which is often overkill. It's surprisingly useful to be able to heat water at non scalding temps. Especially for cleaning tasks, actually.

Ice cubes can water down your drink. Use a large, frozen, steel ball bearing so you can instead get some nice heavy metal poisoning to accompany it.

(Don't actually do this)

They're not a monster

Don't think most plastic straws would melt, but they would probably soften and might infuse more chemicals into your beverage than it would if it were cold. At this point I'd just go for the obvious solution of repurposing an old heat exchanger from an AC unit or something. The strange taste will go away after a few times (probably).

Yeah, I won't drink anything hot out of plastic anymore: Corpos lied to us for decades that it was safe but it wasn't and now we're full of all sorts of terrible shit. The straw probably wouldn't deform, but it probably would leech all sorts of chemicals into the water.

It's plastic not wax

MacGyver gets bored when he doesn't have something important to do.

It would entirely depend on how fast you suck.

Even moderately cool water would work if you just drank slow enough, and ice water wouldn't work if you drank too fast.

I'm sure some engineer could do the math on how cold the water would have to be to cool boiling water at maximum vacuum.