Are you referring to the blue painted sheet metal tube going from the snorkel to to the exhaust manifold? Cold in Texas? Here in Wisconsin 0 is cold. -10 is really cold.
Anyway you are allowed to shivver when it's 40F and build a fire in the fireplace!!
I recommend our very own Classic Mustang parts wanted forum.
My '64 1/2 vert. Ordered May '64. D code 4 speed, handling package, caspian blue, accent group, Ford blue manual top.
'68 vert. driver. Owned since Apr '78. C code AT, AC, PS, P disc B, PT lime gold, standard black interior and top. NOS RF fender and left quarter.New top and folding glass.