Malachi 3:3 (NIV) "He will sit as a refiner and purifier of silver; he will purify the Levites and refine them like gold and silver. Then the LORD will have men who will bring offerings in righteousness,"
Purifciation is the process where something impure becomes pure. Purification is when things are cleaned and made pure. Salt water must undergo purification before it's safe to drink. Some filters do a purification of the air to reduce allergens. Many puriciation processes however use heat. Hence the term "Turning the heat up". So the next time you find yourself in the hot seat, stay put. Allow God to purify you and you will be amazed at the places He can take you.
Psalm 26:2 (NIV) "Test me, LORD, and try me, examine my heart and my mind;"