Graphene oxide starts to reduce at the temperature about 60 but reduction degree is not very high. How long and at what temperature will it be in the warm medium?
As far as I know, insulating feature of graphene oxide is due to functional groups of it. If you want to put graphene oxide at temperature 100 for long time it starts to reduce (reduction degree depends on time and nature of warm medium) and you cannot use of its insulating properties.