A man finally gets his prescription for Viagra. Anxious to try it
out, he takes one as soon as he gets home, and waits for his wife to
come home from work, but, in his excitement he forgets and leaves the
package open on the table and his cockatiel eats all of them.
Seeing the results and panicking the man grabs the bird and stuffs him into the freezer to cool off.

Just
as his wife comes home, the Viagra kicks in  and it's hours later
before he remembers the cockatiel. He runs and looks in the freezer
expecting the worst, only to find the bird breathing heavily, drained
with sweat and totally exhausted.

"What happened?" the man asks, "You were in there for hours and yet you're not only alive but you're sweating like crazy?"

The cockatiel pants: "Man, have you ever tried to pry apart the legs of a frozen chicken?"