When used cold:

Wrap the mask in plastic and refrigerate for 60 minutes. For more intense cold, place the plastic-wrapped mask in the freezer for 10-15 minutes.
Unwrap the mask and apply to the face.

NB! Never freeze the mask fully! The pearls then harden and are no longer usable.

When used warm:

Soak the mask in hot (not boiling!) water for 10-15 minutes. Remove from the water with tongs and dry with a clean towel. Gently place on the eyes.