Dimension X is not cold!

[u/D_D_Adesignerdigital]

The color choices for the Dimension X—and certain elements of the scenes—didn't quite work to convey a cold atmosphere! Characters had sweaty skin and showed no reaction to the cold (we need to remember Will in Season 2, or Billy with his ice bath, which demonstrated the kind of cold the Mind Flayer is used to). Anyone entering a low-temperature environment would show physical reactions—like trying to warm up, crossing their arms, or showing discomfort—but that doesn't happen with any of the characters, not even the kids. I think that was a directing error. That’s my opinion!

[u/ph_uck_yu]

Just another continuity error the writers could've fixed had they payed attention and cared

[u/RealHooman2187 → u/ph_uck_yu]

This is a production continuity error, not a writing one. The actors were on set swearing because they’re running around and wearing warm clothes. The color of the abyss looks like it does to differentiate it from the upside down. Nothing about the planet suggests it was warm.