The Thermaflux Armor is the third armor in the game. Ratchet may purchase it once he touches down at the Agorian Battleplex in the Korthos Sector. Since the player can choose between Lumos and the Battleplex, it is possible for the player to use the Thermaflux Armour on Lumos if they are having trouble. It costs 50,000 bolts and uses an advanced Nanotech circulatory system 30% damage protection. Visual changes include the addition of a visor and larger kneecaps. Assuming Ratchet buys this armor as soon as it is available, the Thermaflux Armor is the set worn by Ratchet for the longest in A Crack in Time.
- The prefix 'Therma' is a biological term meaning "heat" perhaps implying that the armor is capable of heating the wearer. The armor is appropriately colored orange.
- The Armor of A Crack in Time is unique among all Ratchet games in the fact that it is in fact holographic armor. This allows for Ratchet to retain a consistent look throughout cinematics and in-game cutscenes. However, there are some differences between a scene and gameplay. The most noticeable one is that the lights for the armor turn off during scenes, and Ratchet's helmet retracts, leaving his cap visible. A more easily missed difference is that the emblems are always that of the Holoflux Armor no matter what type of Armor Ratchet is wearing at the time. The final difference is that the shoulder pads are always the shorter Holoflux variety.
- The -flux armor in A Crack in Time resembles the Lombax Armor worn by Azimuth and Kaden, particularly the large circular light on Ratchet's chest, which is placed on the right side.