7 Days To Die Heat Map

“Alright, time to fire up the auger. I have mining to do.”
*a shriek nearby*
“Oh, come on, not again. Why do they always show when I’m mining.”

So, you’re here to learn about the Heatmap. The Heatmap is a straightforward thing to explain.

It’s a mechanic within 7 Days to Die that is affected by player activity. Everything you do will “raise the temperature” of the Heatmap. This isn’t something that can be seen while you are playing. The more active you are within an area, the higher the chances of zombies appearing.

While moving around, turning things on, firing your weapons, the chunks around will begin to warm up. The area affected is 16 X 16 blocks. Any heat generated in a block will affect that block and any blocks connected to it. When you leave that area or stop generating heat, it will slowly cool off.

Heat is accumulated on a 100.00% scale and will constantly increase and decrease.

Effects of Heatmap

When the Heatmap reaches a high enough level, there is a chance it will be cut in half, and a certain event will happen nearby.  The higher the heat level, the more likely an event. If the heatmap reaches 100 points, it will instantly reset to 0.

Horde

If the heatmap in an area has been reset too many times, it may spawn a Pitstop Horde. This horde will vary in difficulty. The difficulty is also based on how often it has been reset.

Unlike a wandering horde, a pitstop horde may include Special Infected zombies, which can cause more problems for the player. A pitstop horde is focused on destroying whatever is adding to the heatmap. A pitstop horde will not happen during Blood Moon but can include Screamer, Demolisher, Feral Wight, and more.

Screamer Zombie

Scouting is now done by a Screamer, which will wander towards the affected area. Kill the Screamer quickly, and without being seen. If the player is spotted and it gets off a scream, random zombies will appear and begin heading towards the player. If the screamer is not killed fast enough, it may spawn a horde. Even if the screamer doesn’t notice the player, it will start to summon additional zombies, which will then begin to storm the block that is generating the heat. And they will attack anything that is in their path.

What affects the Heatmap

Heat is generated through unseen heat events. Each heat-generating effect has a strength value that will contribute to the heatmap. If you use 2 campfires for 30 in-game minutes that would generate 2 events (as 30 minutes is only long enough for each campfire to make one event) each event would have a strength of 5 and so the heat for the chunk would be 10%.

Using Blocks

Using the following items will generate heat.

• Strength: The Percentage of heat an event will contribute.
• Frequency: The time, or Number of ‘ticks’, between heat event creations.
• Lifetime: The time, or Number of ‘ticks’, until an event expires.

Upon starting your activity, that will count as 1 tick, and it will add ticks every time the frequency timer is reached, so long as it is active.

Ticks

If using the default game time, you will have 1000 ticks every in-game hour or 1 tick every 3.75 seconds.

An example

According to the table above, each Forge generates 6 heat every in-game hour, thus running at the default game speed of 2.5 minutes. These heat events will stick around for 5 in-game hours. This means, with 2 forges constantly running, without any other heat sources after 2.5 in-game hours, the chunk heat would be (6 [heat strength] * 3 [number of events]) * 2 [number of forges] = 36%. After 8 hours, the maximum for each forge will have been reached and thus, with reference to the table above, 30%*2 = 60% total heat in the chunk. This maximum would be stable until new heat sources are added, or the forges turn off.

Dissipation

In the file Stealth.txt, the heat map time is defined as “the time in seconds it takes for the heat to dissipate. Dissipation is not modelled. It’s instant off after the programmed time.” However, it appears to be contradicted in blocks.xml by a comment that states, “HeatMapTime decay in x seconds, and scales with game time” this comment is frequently misinterpreted to mean decay is modelled. It is NOT. Heat events do expire after a certain amount of time without any depletion in between. This refers to torches, candles, and burning barrels that follow a different rule set (see below), presumably for optimisation reasons. They are more common than the other heat-event producing blocks.

Flickering Fires

Any flickering fires (Torches, candles, and burning barrels), when placed by the player (not as part of a prefab), produce heat ticks. However, unlike other sources of heat/ticks, events from blocks do not emit in line with an interval. Instead, they generate heat ticks simultaneously every real-world minute. This is likely for performance reasons. If they were ticking normally, they would have a frequency of about 666. However, this isn’t easy to measure. The more important fact to remember is that candles are half of torches and barrels, therefore preferable.

For example: At default game speed, 60 minute days, a single torch adds 0.5% heat every real-world minute. 10 torches would reach 100% after 20 real-world minutes. However, with 120 minute days, a single torch adds 0.25% per real-world minute. 10 torches would get 100% after 40 real-world minutes.

Generating maximum heat

If you are looking to purposely generate as much heat as possible, and draw in screamers (screamer farming) to a specified area, then 25 campfires fully loaded with wood will consistently reach and maintain the heat map at 100%. Once it reaches 100%, you can turn 5 of them off, as you will no longer need the additional ticks to maintain the heatmap at 100%. One should note that only 4 campfires are required to reach 100% heat every so often.

Starting an auger 100 times will instantly spawn a screamer. With an average auger RPM of 300, it allows spawning of 3 screamers per min.

Using Items

Firearms, explosives, and interacting with objects will generate heat on a “per-use” basis.

Harvesting and Mining

Cutting down a couple of trees will not add to the heat map. However, cutting down many trees within a small area will generate heat. And it can grow exponentially if you are using a chainsaw to do the job.

This also goes for mining. Mining a small amount of ore will not add to the heat map. If you do a large amount of mining, like I do, with an auger, you better be ready to have visiting zombies.

While you are hunting, if you use a bow or other quiet weapons, you will not generate enough heat to worry.

Metallic & Glass Objects

Dismantling objects with a wrench or damaging a metallic object using another metal tool increases the heatmap, with each hit, by 0.1 for 60 ticks. Using tools with higher block damage will result in fewer ticks due to hitting the object fewer times. Bashing open a safe also increases the heatmap, but at an even higher rate due to the high durability of safes. Lockpicking a safe is the best course to keep from generating ticks to the heatmap.

Damage done to any metallic objects by zombies will also add ticks to the heatmap. Therefore scrap and steel structures, while stronger, may end up drawing more zombies than the player can deal with. This leads to some players building a flimsy outer wall/fence to prevent wandering zombies from hitting strong defences, which are often made of louder materials.

Upgrading and constructing using metal will also increase the heatmap. This counts for building and upgrading blocks and doors to the higher metallic tier. Additionally, metal Traps such as the spinning blade, log iron spike, and barbed wires will generate heatmap ticks as they take damage from zombies and players alike.

What Does NOT Increase the Heatmap

• Running – It does not increase the heatmap but will generate noise that may attract nearby zombies.
• Non-Fire based light sources, such as spotlights.
• The use of a Generator, Battery, and Solar Bank will not increase heat passively even when being used (though a very small amount is generated when opening them)
• A player bed also does not contribute to the heatmap anymore.

Compound Heat Generation

Everything you do, whether it is open and closing containers, running single or multiple campfires or forges, will compound to increase the heatmap.