Just like the fuel gauge, there have been a rash of temperature gauge wiring issues posted recently so to help in this regard, here is a diagram of what a typical temperature gauge system looks like. It is in effect identical to the fuel gauge circuit. The temp sender is the equivalent of a fuel gauge sender differing only in appearance. Both are variable resistors that range from 33 - 240 ohms. The gauge is also identical except it is calibrated in degrees rather than from Empty to Full.
Temperature senders are of two types, the screw-in variety and the contact type. Both are shown below.