Where to keep cakes in this weather?

[storminabuttercup]

Just about to fill a cake with buttercream, where's the best place to keep it? Will it go hard in the fridge?

Where's the coolest place you have? Id be tempted to pop it in tupperware and leave it in the bathroom (yes I know it sounds gross, but its the coolest place we have).

Everywhere is pretty hot tbh. Maybe I could pop it in Tupperware then in a cool bag with an ice pack? It'll be gone by tomorrow anyway

That should be fine. The fridge will make it go hard. Better be on the safe side and eat it!