The Thermal Cube 5e – Best Magic Item in Icewind Dale?

The Thermal Cube 5e - Best Magic Item in Icewind Dale?

Icewind Dale – the coolest (literally) location in the Forgotten Realms. It is a vast arctic tundra located in the Frozenfar region of the North of the Sword Coast. It’s bleak setting with a temperature of well below freezing, with snow banks and frozen peaks that stretch for miles . For some players, this area is a tough place to express creativity outside the local settlements of 10-towns. Fortunately, there are plenty of ways to heat up the game! Today, we’ll take a look at a useful magic items that will defrost your players brains: The Thermal Cube!

In this article, we’ll cover an item recommendation from the Icewind Dale 5e campaign book: The Thermal Cube.

  • What is the Thermal Cube? 
  • How do you use the Thermal Cube?
  • Is the Thermal Cube safe to actually handle?


The Thermal Cube is a Wondrous Item introduced in Icewind Dale: Rime of the Frostmaiden. Strangely enough, it is tagged as a “common” item. The description from the Rime of the Frostmaiden campaign book reads:

“This 3-inch cube of solid brimstone generates enough dry heat to keep the temperature within a 15 feet radius of it at 95 degrees Fahrenheit (35 degrees Celsius).”

The Thermal Cube 5e - Best Magic Item in Icewind Dale?

As a GM, I completely understand how one might wonder how this glorified hot potato could be a useful item. So here’s the value:

  • The Thermal Cube doesn’t require atunement, so anyone can use it at any time.
  • The description doesn’t mention its weight, but a 3-inch cube is likely less than a pound. This means players could carry more than one!
  • It is not a wondrous item, it’s common! So they are likely purchasable in some shops (The campaign book recommends a 100gp price point for common magic items)

We can also assume that the Thermal Cube can be used as an improvised weapon! Use your Strength to make a melee weapon attack, or throw it a range of 20ft!

Now, here is where things get interesting!


Because the description of the Thermal Cube is so lackluster, it opens up the possibilities of creative use to over 9000! 

Off the cuff it’s easy to see a practical use of warming the entire space of an igloo, cave, or domicile while the players are traveling through the Dale, but here at Nerd Night News we know that the best uses of fantasy items are the most impractical ones! And in order to figure out just how ridiculous the potential for the Thermal Cube is, a question came to mind: Since the Thermal Cube description states that it works by generating heat, the cube has to be hot enough to keep the air 15 feet away 95 degrees Fahrenheit. 

The Thermal Cube 5e - Best Magic Item in Icewind Dale?

Luckily, I found a fellow Nerd on Reddit who already did the math, linked HERE

They came to the conclusion that the cube’s temperature was calculated to be 2093K or 1820°C or 3308°F which makes this common item able to destroy anything – if your GM likes science!

Not only would that make the Thermal Cube twice as hot as fire, it would completely change the dynamic of possible uses and exploits. Players could melt their way through many aspects of Icewind Dale including its creatures and its inhabitants, then furnish the Cube in a cast for later use. Granted, the cube itself is only 3 inches across, which may make it difficult to get to creatures inside ice fortresses, but tactically for one creature, it could mean the intimidation check of a lifetime.

What’s that? It has become too powerful? Don’t worry, you can nerf the cube by having other creatures make a dexterity saving throw to get out of the cube’s way, assigning an obligatory amount of dice damage to the cube on a failed saving throw, and having creatures only take half as much damage on a successful one. That way, if the side of the cube brushes an important creature on a failed save, it won’t auto-kill your plot device, mini-boss, or BBEG.


In Icewind Dale: Rime of the Frostmaiden, the Thermal Cube is most certainly meant to be used as a substitute for a campfire. Given the math behind making it an unreasonably overpowered item, the answer regarding the Thermal Cube’s safety is completely up to the GM. If your table likes practicality, they can utilize the cube to pressure creatures into a failed saving throw, or just use the cube’s space melt creatures inside its intense aura. If your table is more shenanigan oriented, the Thermal Cube will likely make a warm welcome to the arsenal of silly items used to break puzzles, traps, and dungeons you throw at them.


If you’re the type of GM to transform this common magical item into an elaborate trap hidden in plain sight, a villain’s power source containing a monstrous creature, or just taking it out of the players hands and into your own evil steepled fingers, the scenarios for interactive environment pieces open up like a filleted knucklehead trout!

Personally, I think it was a happy technicality to write in the description that the Thermal Cube generates heat instead of stating that it magically maintains heat in a specific radius – and we all know that “technically correct” is the best kind of correct. 


The Thermal Cube has the dynamic potential to be either the most mundane or most interesting thing players can come across in the setting of Icewind Dale. It’s also a great item for GMs to have in their back pocket as an encounter or set piece. Who knows? Maybe it even contains an ancient evil deity. That’s the best part about Dungeons and Dragons – it’s a game of unbound imagination, and the Thermal Cube is an amazing example of how something often overlooked can become one of the biggest hooks in your campaign.

So before you introduce the Thermal Cube to your campaign, make sure to set a precedent on its unique properties!

Praise the Cube

Thanks for reading! But why stop? Check out this article on The Best D&D5e Magic Items for a Rogue HERE

What experience do you have with the Thermal Cube? What magic items do your players love to mess around with? Let us know in the comments!

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