Finding the Source Krakle in Un'Goro Crater wants you to find the hottest area of Fire Plume Ridge.
Whenever you find a hot spot, right click the thermometer to check the temperature. Keep looking until you find the hottest one.
Western Plaguelands Alliance Quest
All Along the Watchtowers Using the Beacon Torch, mark each tower in Andorhal; you will need to stand in the doorway of the tower to successfully mark it.
Once all four towers are marked, return the Beacon Torch to Commander Ashlam Valorfist in Chillwind Camp, Western Plaguelands.
Blasted Lands Alliance & Horde
The Stones That Bind Us - (Step 3) Free nine Servants of Razelikh, three Servants of Sevine, three Servants of Allistarj, and three Servants of Grol. Return to the Fallen Hero when your task is complete. You must remain within close proximity of the stones or the process will fail.
Winterspring Alliance & Horde
Are We There, Yeti? - (Step 3) Take Umi's Mechanical Yeti and scare her friends with it:
Legacki in Everlook (Winterspring)
Sprinkle in Gadgetzan (Tanaris)
Quixxil in Marshal's Refuge (Un'Goro Crater)
When you are done, bring the Mechanical Yeti back to Umi.