While you can carry a reasonable number of disposable vapes in your hand luggage, remember that vaping inside the aircraft is strictly prohibited
For starters, theres this rumor that smoking speeds up your metabolism, making it burn calories a little faster
However, this increase is not observed for exclusive e-cigarette users (15% increase, statistically insignificant), consistent with two recent studies (here and here)
Establishments are required to post signs stating that sales to minors are prohibited.6 Minors are prohibited from buying, possessing, or using e-cigarettes.6 The sale or distribution of e-cigarettes and e-liquid to persons under age 21 is prohibited
Text messages to help quit smoking or vaping
As best as I can tell, Cuban flag carrier Cubana was the last airline in the world to ban smoking in 2014