I remember my kids doing that. I'd always take them outside if it lasted for more than a few minutes, but sometimes where you're there alone you don't have a choice and the kid is inconsolable. Parenting can suck at times.
Our oldest just turned 5. He got read the riot act a few times especially during those 2/3 years.
HOWEVER - I've usually tried to avoid the outright "threats only" tactic.
Step 1, certainly with a young kid, is calm them down enough so they can listen and comprehend again. Even if it goes against the natural impulse of throttling, a good hug and telling them you love them works (obviously for small kids).
Step 2, explain why the behavior is bad. Disrupts others, compare the behavior to other people in the store so they see it isn't accepted, etc.
Step 3, offer some sort of goal for them as an incentive. I don't always do this, especially, for example, as our first gets older - good behavior should be an expectation. But he will also get surprise rewards for good behavior.
If both parents are together a child does stand a chance of getting taken out to the car.
As for other people kids? I love it when they misbehave. A sweeter sound I have never heard, than it being someone else's little varmints acting up. Aaaaahhhhh