hot factor = when u keep on reciting some dhikr, it's effect starts showing on you and there are symptoms like people getting fat or fainted etc... because of excessive zikr. To stop this people are asked to read durood. Durood is sending salutation to prophet and asking for peace for the ummah. By reading durood we feel peace. It is also called as "durood sharif" in indo-pak. wird = supplication wird = supplication