Thermal Sorcery

Thermal Sorcerers are capable of absorbing heat and releasing it in large bursts.

Heat Absorption: Absorbing the heat from an object or attack, causing it to freeze. 

Thermal Speaker

The arcane magic you command is infused with element of fire and ice. You can speak, read, and write Primordial. Knowing this language allows you to understand and be understood by those who speak its dialects: Aquan, Auran, Ignan, and Terran.

Thermal Magic

Starting at 1st level, as a bonus action, you can cause thermal air to surround you after you cast a frost spell, you can cast a fire spell at the same level.

Boiling Blood/Cold Blooded

At 6th level, you gain resistance to fire and cold damage. In addition, whenever you start casting a spell of 1st level or higher that deals fire or cold damage, flame or snowflakes erupt from you. This eruption causes creatures of your choice that you can see within 10 feet of you to take fire or cold damage (choose each time this ability activates) equal to half your sorcerer level.

Thermal Guide

At 6th level, you gain the ability to subtly control the weather around you.

 You can increase or decrease the temperature around you up to 20-foot-radius sphere centered around you.

Thermal Fury

Starting at 14th level, when you are hit by a melee attack, you can use your reaction to deal fire damage or cold damage to the attacker. The damage equals your sorcerer level. The attacker must also make a Strength saving throw against your sorcerer spell save DC. On a failed save, the attacker is pushed in a straight line up to 10 feet away from you.

Heat Wave

At 18th level, you gain immunity to fire and cold damage.

You also gain a magical flying speed of 60 feet. As an action, you can scorch or freeze the area around you creating difficult terrain up to 60ft. You can only use the third part of this ability once per long rest.