Does Thermo Beam destroy both a hidden Zhonya's Hourglass on the battlefield and a non-hidden Zhonya's Hourglass in base?

Ruling: Thermo Beam only destroys the non-hidden Zhonya's Hourglass. The hidden card on the battlefield is not affected.

Nuances:

• Hidden cards don't "exist" in the game before they're flipped, so they are not affected by effects that would target or destroy cards with matching names