Do you need insulation wrapped around your fractional distillation apparatus?

It could be a good idea because insulation gives heat out therefore speeds up the reaction in the distillation as molecules have kinetic energy to move faster.
However the disadvantages is as you might know that in the bottom of the distillation is the less volatile compunds which need so much energy to break such as bitumen so insulation would cause them to vapourise which you may not identify which stays in the bottom or top as heta vapourises substances