Re: what is a safe way to heat a metal and find its electrical resistance

Unfortunately, I cannot think of a economical, safe, way for you to do 
this.  At zero degrees Celsius, 1 meter of copper has a resistance of 
about 15.43 nano-Ohm (1 nano-Ohm is one-billionth of an Ohm, or 
0.000000001 Ohm); at room temperature (around 21 degrees C), the 
resistance is roughly 17 nano-Ohm; and at the boiling point of water (100 
degrees C), the resistance is roughly 22 nano-Ohm.  The problems that I 
see are that you will need lots of copper (expensive), or an Ohm meter 
that can measure very small resistances (also, expensive).  Also, you will 
have to be able to control and measure the temperature of the copper 
(this, also, is not a trivial, inexpensive task).

For the above information, I referenced the "CRC Hanbook of Chemistry and 
Physics", David R. Lide (ed.), 83rd edition, 2002.