Treating for mites at night - how cold is too cold?

[Webbykins]

Preparing to treat my flock with elector psp for mites. It's 57 now with a low of 44 tonight - too cold to spray the hard to catch hooligans at roost tonight?

 

[GodLovesU]

I just use poultry dust.

 

[Webbykins]

I just use poultry dust.

The kind with permitherin? I have the garden and poultry dust with permitherin and haven't used it yet