In the long method the heap rises quickly and may reach 70 degrees Celsius within 24 to 48 hours. The DMR farmer folder describes 65 to 70 degrees in two or three days and calls it a good sign.
There is an upper limit. DMR states that above 80 degrees in the central core is not desirable, because the core goes anaerobic and the friendly thermophilic flora is lost. A heap hot in the middle and cold at the edges is not composting evenly; it is two heaps in one, and the turning schedule exists to swap them.