The question is pretty direct. What are NAFTA, heptane good temps to heat up for extractions?

It is weird I hace not seen any TEK that says it. I think 50 C is good for NAFTA but not sure. HELP!!

Warm, doesnt have to be too hot, id say 40C is good

For aliphtatic hydrocarbon solvents like naphtha, heptane etc. 35-40 °C, not more.

At 45 °C I already observed pulling of oils, so 50 °C will certainly be too much.

You can heat up the mother liquor instead, the solvent will heat up from it easily (water has much higher specific heat capacity than naphtha). Ideally, both solvent and the aqueous mother liquor should have same temperature. If you use separatory funnel, make sure to vent it frequently as the expanding vapours create great pressure.