The Thermal Visor is the second Visor upgrade in Metroid Prime found in the Space Pirate research lab in Phendrana Drifts. It detects heat signatures given off by enemies and other objects. The Thermal Visor does not have the radar present in the Combat Visor.
The Thermal Visor was created as part of an Imaging research project being conducted by Space Pirates. Their experimentation with Phazon revealed that Phazon Ore was bound together by Phazon Energy, and that the highest concentrations of radioactivity could be detected using Thermal Imaging. It was also determined that weaknesses in the casing of Phazon ore could be detected via Thermal Imaging, which could potentially undermine many of their Phazon experiments, such as Project Titan and their most successful venture in that project, Thardus.
The Thermal Visor is especially useful in targeting enemies that utilize stealth tactics, or that cannot normally be targeted with the Combat Visor.
Some enemies, such as the Shriekbat, cannot be detected with the Combat Visor until they are prepared to attack; with the Thermal Visor, Samus, can lock on to them at any time by tracking their heat signature. The Thermal Visor can also be used to target Shadow Pirates, who use sophisticated cloaking technology in their stealth operations; additionally, the creature Metroid Prime is capable of rendering itself invisible to certain spectra, but occasionally the Thermal Visor can still be used to target it.
Other uses include the ability to reveal vulnerabilities in Phazon ore, such as while battling Thardus, or the heat signatures given off by various technologies including the Elite Pirate's plasma cannons. Samus can also use the Thermal Visor to detect the heat signatures given off by dormant Power Conduits, and use the Wave Beam to recharge these conduits.
While useful in cool areas where heat signatures are readily apparent, such as Phendrana Drifts, the Thermal Visor can be overloaded by radiation or rendered effectively useless in superheated areas, such as Magmoor Caverns.
The Thermal Visor will show the weak points of certain foes. Use the Thermal Visor to see in total darkness and poor weather conditions. Brightly lit areas, explosions, and intense heat can impair the Thermal Visor. Enemies with temperatures close to their surroundings will be tough to spot with this Visor.
- "Once Samus finds the Thermal Visor, she can track enemies using their heat signatures. Not only does this visor help locate enemies hidden in dark areas, but it can also be used for acquiring alternate targets on enemies. A thermal scan can often find a hidden weak spot on an otherwise difficult enemy. Not only that, but thermal scans can show other clues that the naked eye can't discern; if you run into a dead end, try scanning the entire area with a Thermal Visor sweep." Metroid Prime Instruction Booklet, Pg 19
- "Imaging research is being conducted in the containment Vault area of this facility." —Scan Data (Metroid Prime)
- "Phazon ore appears to bind through Phazon energy. Thermal Imaging is required to detect the highest concentration of radioactivity, which serves to bind the stones together." —Scan Data (Metroid Prime)
- "Phazon ore is extremely durable and blast-resistant. Although the armor-like qualities of this shell provide ample protection, Thermal Imaging can be used to detect weak areas in the casing. Improvements must be made to this shell in the event that these weaknesses are found by aggressors." —Scan Data (Metroid Prime)
- "Territorial ceiling-dweller. Body temperature peaks at 121° centigrade. Shriekbats have high internal temperature, making them easy to spot with thermal imaging. They roost on cave ceilings while hunting for small prey. Fiercely territorial, they dive-bomb anything that wanders near." —Logbook (Metroid Prime)
- "The Shadow Pirates are Pirate forces that are trained and equipped for stealth operations. A select group of Space Pirates have access to sophisticated cloaking technology. This gear drains high levels of power, however, forcing them to rely solely on melee weapons in battle. Use enhanced detection gear when fighting these units." —Logbook (Metroid Prime)
- "An animated, sentient creature of stone charged with Phazon radiation. The Phazon radiation given off by Thardus negates auto-targeting systems, preventing lock-on. It may be possible to acquire alternate targets with a different Visor. The chaotic nature of Phazon irradiation leads to instability in its structural integrity. Thardus can encase targets in ice, and its colossal size and strength make it a formidable opponent." —Logbook (Metroid Prime)
- "Unit has extreme thermal signature due to lack of shielding. Cannon connected to energy-siphon systems to augment performance. Avoid Beam weapon fire when energy-siphon unit is active." —Scan Data (Metroid Prime)
- "This door has no power. A nearby power conduit must be energized for it to open. A blast of electrical energy will energize the conduit. The conduit radiates some heat that is invisible in the normal spectrum." —Scan Data (Metroid Prime)
- "This can detect the temperature of your surroundings. It may show some enemy's locations or weaknesses that you can't see with the Combat Visor, and will show you the areas where the temperature is abnormal." Metroid Prime: Trilogy Instruction Booklet, Pg 17
- "The Thermal Visor will show the weak points of certain foes. Use the Thermal Visor to see in total darkness and poor weather conditions. Brightly lit areas, explosions, and intense heat can impair the Thermal Visor. Enemies with temperatures close to their surroundings will be tough to spot with this Visor." —Samus's Notes (Metroid Prime)