Munchkin Apocalypse

[LoneWolf]

I just received Apocalypse today and already have a question concerning the seals. Since nothing happened after I kicked down a door, I decided to loot the room. The card I picked was "Disaster! Giant Meteor: Open A Seal AND Lose An Item" My question is, if I pick such a card (which in the end is is a curse card) during the room looting phase, do I keep it in my hand like usual, or do I have to play it instantly because it applies to a seal?

If I can keep it, I don't really see the point. What possible strategic use could there be in doing so?

Could you please clarify.

Thanks.