Glowing Jell-O Shots

Make the first layer: Pour one cup tonic water into a pot over high heat. Once it comes to a boil, add the pineapple Jell-o mix. Whisk until the mix has dissolved, then pour in half a cup of water and half a cup of vodka. Stir to combine. Pour the Jell-o into shot glasses, filling them about two-thirds of the way up. Place in the refrigerator to chill, 30 to 35 minutes. Make the second layer: As they set, start making the orange Jell-o, following the same process used for the pineapple Jell-o. Top each of the pineapple Jell-o shot glasses with the orange Jell-o mixture. Return the shots to the fridge to set, 2 to 3 hours.