NO, NO, NO! What you need, is a stirred oil bath with a thermostat in which to put your current source, current sink, V references... There is no hope of studying a small temperature sensitivity without controlling the temperature of the parts you're trying not to study. Instead of 0.1% (100ppm per C with a 10C temperature span), go for 0.001% (100 ppm per C with a 0.1C span).
In fact, you'll want two oil baths, one for constant temperature, one for variable temperature.