Take a mixing bowl, add the Jello, and pour the boiling water. Stir the mixture until the Jello is completely dissolved.
In the same bowl, add the cold water and then the vodka. Ensure everything is thoroughly mixed together.
Carefully pour the mix into shot glasses or any other small container you have.
Pop them into the fridge to cool and set for about 2 hours. Serve once the shots have become firm.