Brian Brushwood teaches you how to do the hot seat card trick. You need a regular deck of cards and the 10th card from the top should be the 3 of spades. The spectator chooses a number between 10 and 20. He takes the cards and deals down that amount of cards from the top. Next, add those two digits and deal that amount of cards. There's a piece of paper in plain view the whole time with the card prediction. Write the 3 of spades on the piece of paper using a regular pen. On top of it write 8 of clubs using a Frixxion pen. The ink from that type of pen disappears when close to heat. When the spectator flips that top card and it's the 3 of spades, you are made a fool. Then you put the piece of paper next to a heat source and the 8 of clubs transforms into a 3 of spades.