For 10 points, name this variable, which in humans is elevated by pyrogens in fevers.
This variable affects transcription by setting the confirmation of the FourU and ROSE elements. In rats, neurons sensitive to this can be found in the PO/AH region. Lee Hartwell developed several S. cerevisiae mutants sensitive to this variable.  In protein production in prokaryotes, lowering this variable during induction generally leads to increased yields. It's not electric current, but increasing this variable temporarily is a common way of chemically (*) transforming cells with plasmid. It's not pain, but information about this variable is carried by Lissauer's tract through unmyelinated C-fibers. In PCR primer design, the forward and reverse primers should have similar values for this variable "sub m." A sudden rise in this variable causes upregulation of the hsp protein family. For 10 points, name this variable, which in humans is elevated by pyrogens in fevers.
This variable affects transcription by setting the confirmation of the FourU and ROSE elements.
heat or temperature