A-Level Physics: What is the current needed to maintain the wire at a steady temperature of 387∘C?
Hint 1: 

You have two scenarios; one at 57 degC and one at 387 degC. You need to find an expression (of something) that has the same meaning at both temperatures then you can equate those two expressions.

I've got the right answer BTW so what can you say about the power lost as heat at 57 degC and the power lost as heat at 387 degC?

Hint 2 (some time later):

You should equate watts per degree centigrade at both temperatures - derive a (fairly) simple formula that gives you watts per degree C - this is constant for both scenarios.