Heating your home with a fireplace is fun and beautiful. Few things are nicer than snuggling up in front of a warm fire on a cold night. Managing your fire is important to fully enjoy the experience. Fire requires three things: heat, fuel, and oxygen. Once you have a fire established, you can control the temperature and length by managing the fuel and oxygen ratio. If a fire is burning too hot, there is too much oxygen for the fuel; if it's burning too cool (e.g., smoking too much), there is too much fuel for the oxygen.
Close the air intake for wood stoves and closed, front fireplaces. This will cool down the fire, and cause it to burn more slowly. Do not completely close the air intake, or the fire will die due to lack of oxygen. Do not close the flue to the chimney, because this will cause your house to fill with smoke.
Reposition the log in the fire to reduce the airflow around it. Push it farther into the coals, or pull ashes over top of it with the fire poker.
Remove the log from the bed of coals, and place it to one side inside the fireplace. This will remove some of the heat from the fire triangle and reduce the intensity of the fire.