You have the ability to elevate the heat of your flames to a higher level.  On your turn, you can harness the white flames as a bonus action. 

When you activate the white flames, roll 1d10.  This is the number of rounds the white flames last.  (Max 1 minute).  It ends early if you are knocked unconscious.  You can also stop the flames on your turn as a bonus action.

The white flames grant you the following bonuses:

• When dealing fire damage, add one extra dice of the same type to the roll
• You gain an extra 5 feet of movement speed
• You can use the dash action as a bonus action

Note: You must make a DC 15 Con save if something triggers a strong emotion in you.  Doing so causes your flames to go out of control.  You deal 4d6 to all creatures within 15 feet of you.  If you rolled less than a 10, you gain 1 point of exhaustion.

Once you have use the flames the number of times equal to your proficiency modifier, you must finish a long rest before you can use this ability again.