Here's the part most people mess up. The TSA allows e-cigarettes and vaping devices in carry-on bags only. They are not allowed in checked luggage. This is because of the lithium batteries—they can catch fire if damaged, and a fire in the cargo hold is a much bigger problem than one in the cabin.

So, pack your vape in your carry-on. Make sure it's off and the battery is protected. If you have spare batteries, keep them in a protective case. Loose batteries in your pocket can short-circuit, which is a real fire risk. I've seen people toss them in a bag with keys and coins—don't do that.

Each airline may also have its own policy, so it's worth checking their website or calling ahead. Some airlines have stricter rules about the number of devices or batteries you can bring.

Now, what about using your vape on the plane? That's a hard no, even if you're on a long flight and feeling the urge. You'll have to wait until you're outside the terminal.