Equal temperature
When it is blocked by an insulator or if your in the North Pole
when you close the heat off and let it cool down.
Heat will stop flowing between the two bodies when they reach thermal equilibrium, meaning they both reach the same temperature. At this point, there is no longer a temperature difference driving the heat transfer, so no more heat will flow between them.
It'll stop flowing when all of the material has reached th same temperature.
When the heat is traveling in the form of radiation, there's no reason for it to stop as long as the source is active. In the conductive and convective situations, the flow of heat from one material or object to the other stops when their temperatures are equal.
When you stop breathing.
stop
You cant!
Heat flow between two objects stops when they reach thermal equilibrium, meaning they have the same temperature and there is no longer a temperature difference to drive heat transfer. At this point, the heat transfer between the objects ceases.
When the heat is traveling in the form of radiation, there's no reason for it to stop as long as the source is active. In the conductive and convective situations, the flow of heat from one material or object to the other stops when their temperatures are equal.
Heat stops being transfered to another object when the other object becomes hotter than the original object the heat was radiating from (naturally). Its a law of thermodynamics that heat always goes from a hotter surface to a colder one.
Veins have valves which stop the blood from flowing backwards