How do I destroy an object only during a certain frame?

Hello Everyone

This question is going to sound rather long winded but I just wanted to be clear...

So in the game I'm working on, it all revolves around timing. What I need to do is create an event in which projectiles damage the main character sprite only when he isn't blocking. So there are two animation frames in my simple game, blocking and not blocking. How do I make it so that the character is destroyed when hit by a projectile during the non-blocking animation frame but he blocks it and does NOT die when the blocking animation frame is playing?

Thank you in advance.

projectile on collision with character

-- character animation frame = 0

character destroy

-- else

projectile destroy

You're awesome, thank you so much! I'll test it out now.