What vids did you watch?
Because the red-wrist blades don't exist. They showed up in the early promotional images and trailers, but it wasn't in the final game.
If someone can correct me in my statement please do so, because I can't for the life of me remember ever getting the red-heated-wristblades, and I remember that they weren't placed in the final build of the game.
I'll have to find my copy of the game. I know that I got all the upgrades...so I'll know if those wristblades are in there or not. It's honestly been so long since i played it.