Both keys and their respective chests are located in different locations. Finding the key and the chest can be a bit tricky, as you must carry out plenty of walking around to get to the spots. Both chests contain unique rewards for finding them. Here in this guide, we will show you the exact location to recover the key and the hidden chest in the game.
How to Acquire the Frostbitten Key

The Frostbitten Key is located in the Ice Cream Cart, south of the map, lying next to a corpse. The exact location in this region is shown above, and here is how to get there. The area in the middle will be cold, so wear any gear that provides Chill Reduction. With the right gear equipped, make your way center of the Ice Cream Cart, and you will soon find a cone of ice cream in the distance.
Get inside the cone, follow the linear path, and you will get to a fork in the road. Here, take the path on the left. Now you will arrive at the entrance point for a huge open area (remember this spot). Here, turn right, keep heading in the direction, and then drop down next to the upside-down Pink ice cream cone on the floor. Walk forward, head down the slope, and then turn right from the green ice cream cone.
Now go under the yellow cylinder on the left, keep moving forward, and you will soon find a dead corpse on the pink ice cream spillage to your left. Next to the corpse, you will find an Ice Cream Cart Optical Disk and a Frostbitten Key.
Frostbitten Chest Location

After you have acquired the Frostbitten Key, make your way back to the entrance spot, the first fork in the road we encountered. From the entrance spot, turn left, walk forward, and climb on the ice cream packets.
And then make your way to the green ice cream spillage, located right of the ice cream packets. Once you are in the green ice cream spot, you will see a bronze pipe leading to an area with light at a distance. Climb on the pipe and move forward to the spot at a distance.
Go through the vents, and you will see a gear being blocked by icicles around it. Break all the icicles around the gear and go around its back, jump down the hole. Make your way down, and you will find a breakable tooth with Mega Milk Molar inside.

Turn around from the tooth spot, follow the bronze pipe, and it will lead you to an open area. Keep heading straight and head through the gap at a distance, and you will find the chest buried inside the snow.
Rewards: Mint Glob x2
How to Acquire the Sizzling Key?
Location: Statue, east of the map.
You must finish the Networking story quest to get the Sizzling Key as a reward. Here, you must make your way inside the Network Center. You will find the key, Sizzling Key, next to the Go Network Center TURBO Optical Disk on a desk.
The game will state the Sizzling Key as a strangely warm treasure key with a slight cinnamon aroma.
Sizzling Key Chest Location

Location: South of Pine Hill, northwest of the map
After you have acquired Sizzling Key from the Network Center in the Statue area, make your way to Pine Hill, located northwest of the map. Now make your way to the south of Pine Hill to a location as seen in the map above.
Once you reach the spot, crawl along the tree branch, break the Deep Root, and head inside. Follow the tree branch path until you reach the spot with three mushrooms on the right. A bit right of the mushrooms, you will find a huge rock, climb on the rock with your ant buggy, and a bit north of the rocky area, you will find a small hole. Underneath the dried leaf, you will find the chest that requires a Sizzling Key.
Rewards: Spicy Glob x2