Vaping weed is popular, but there are many unknowns about its safety : NPR Texas to ban sales of THC vapes starting Monday KUT Radio, Austin's NPR Station Adding tobacco to cannabis doesn't affect the high, but impacts memory and heart UCL News UCL University College London Do you know the signs your teen may be vaping cannabis? Cannabis vape pens are small, discreet, and easy to hide and many parents don't even know what to look for.