Hot and Cold is a pair of connected islands in the Second Sea, known for its striking dual environment design and its importance in several major progression systems. Located south of Green Zone, the two islands are shaped like tomoe symbols that together form a yin yang pattern, separated by a river running through the center.

The island is split into two contrasting halves: a cold side and a hot side. The cold side resembles an icy tundra, dominated by snow, ice, and pale blue terrain. Its most notable structure is the large Laboratory at the center, a layered facility topped with a glass dome and tied to several important game mechanics. The area also includes a small village on the right side.

The hot side has a volcanic, hell-like environment filled with lava flows and scorched terrain. At its center stands a dark cathedral where Smoke Admiral resides, surrounded by lava pools and curved stone spires. Behind the cathedral is access to the Secret Laboratory, where players can purchase Order Raid chips from Arlthmetic and progress toward unlocking the Cyborg race.

The hot side also features multiple volcanoes, elevated hills, and a large village split into two sections by the central high ground. The front section of this village is especially useful, as it houses several First Sea fighting style NPCs, making Hot and Cold an important destination for both progression and utility.

About Laboratory:

Inside the Laboratory, players will find four color panels. Pressing a panel changes its color. Entering the sequence 🟥🟦🟩🟦 (Red, Blue, Green, Blue) opens a hidden door behind the panels, leading to the raid room through a steep passage, where players can host or join raids.

• The player must not hold anything to interact with the panels.

• The room also contains 2 golden chests and 1 silver chest.