Does anyone know why the downstairs shower is tepid but upstairs hot?!

[Hreatstall]

Please help!

Have you changed the mixer settings?

No nothing has changed at all

There is not enough info here. Are they both the same make? How is the water heated? Are they electric, run off a combi boiler or what?

Are they both electric

Maybe one uses the hot water whereas the other makes its own hot water

Hot water rises!
Your pump isn't working properly!