Have you wondered why a Screamer zombie suddenly appeared in your base in 7 Days to Die? One reason is because of the heatmap, which is a mechanic that puts a constant cloud of dread over the players’ heads. So, continue reading as we dive deep into the heatmap and how it works in 7 Days to Die.

What is the Heatmap in 7 Days to Die?

The heatmap in 7 Days to Die is a hidden mechanic that tracks players’ activities within a specific area. If the "heat" in that location reaches a certain level, a Screamer zombie spawns. Failure to quickly dispatch the special zombie can lead to an undead horde spawning at your location. Understanding how the heatmap works in 7 Days to Die can help prevent Screamers from suddenly appearing in your base. In particular, each generated map is divided into various chunks, which are typically 16x16 blocks each. Additionally, each chunk has a distinct heat level. Adding objects to a block increases that area’s heat level. Also, performing actions in those locations can also generate “heat,” increasing the likelihood of Screamers spawning. Some activities that generate heat include firing weapons, lighting campfires, and dismantling objects. Staying idle at a particular block decreases the heat level. It’s possible to see the heat level of a block by using the command console and activating debug mode. Alternatively, check for nearby signs of high heat, such as flickering lights or by hearing strange noises.

Zombie Scouts

Screamer zombies are the scouts of an area with a high heat map. The appearance of this special undead can be a sign of impending doom to players since the Screamer can summon other zombies like Zombie Dogs, Spider Zombies, and Feral Zombies. Survivors must defeat the Screamer quickly and stealthily. Being seen by this special zombie will trigger its screech, leading to the undead horde.

Heatmap Heat Values

Objects and actions generate heat values called heat events. Each event has a strength level that can accumulate and lead to summoning the Screamer. Actions can generate heat values, although these elements dissipate over time, particularly when the player is idle. On the other hand, objects that generate "heat" accumulate these values over time until the player destroys or disassembles those items. For example, playing a Forge and two Dew Collectors in one 16x16 block generates two heat events per 30 in-game minutes. Note that the Forge generates 6% heat while the two Dew Collectors have 4% heat. A Screamer spawns at 100% heat value, which means this special zombie will appear after about five in-game hours. Additionally, each heat event occurs at a unit called tick. 1 in-game hour is equivalent to 1,000 ticks unless modified by a game or server administrator. With that, here are the heat values for the different in-game actions and blocks:

Blocks

Block	Heat Strength	Tick Frequency	Lifetime	Maximum Heat Generated
Campfire	5	1000	5000	25%
Forge	6	1000	5000	30%
Dew Collector	2	1000	5000	10%
Workbench	5	1000	4000	20%
Cement Mixer	5	1000	4000	20%
Chemistry Station	5	1000	5000	25%
Torches	1	~666*	4000	*
Candles	0.5	~666*	4000	*
Burning Barrels	1	~666*	4000	*

*Generates about a tick per real-world minute.

Actions

Heat-Generating Actions	Examples	Heat Strength	Lifetime
Starting power tools	Starting up (but not continuing to use) the auger or chainsaw	1	90
Most Silenced G1 weapons	Firing a silenced pistol or SMG	0.4	180
G1 weapons	Firing a pistol, desert vulture, SMG, m60, and most turrets	0.65	180
Most Silenced G2 weapons	Firing various rifles except for hunting and AK47	0.65	180
G2 weapons	Firing various rifles, including AK47 and the tactical assault rifle	0.9	180
The 44 magnum	Firing the 44 magnum	0.75	180
Full Shotguns	Firing various shotguns except saw-off	1	180
Silenced Pump Shotgun	Firing the silenced pump shotgun	0.8	180
sawn-off shotgun	Firing the sawn-off shotgun	0.3	120
Silenced hunting rifle	Firing the hunting rifle	0.6	180
Silenced m60	Firing the m60	0.7	180
minor turrets	Firing the junk turret	0.25	180
Rocket launchers	Firing the m136 rocket launcher	0.2	90
Molotov cocktail	Firing the Molotov cocktail explosion	0.2	90
All other explosives	Explosives except the Molotov cocktail	5	300
shooting metal	Every bullet shot at a metal block, regardless of the type	0.1	60
Operating drawbridge	Opening and closing the drawbridge	0.2	90
Large creatures Deaths	The death of most creatures as big as a boar and up fall in here (Though zombies do not seem to be included)	0.2	90
Trader	All trader calls (such as announcing that their shop is open)	0.2	90
Environmental block breaks	Breaking environmental blocks, such as wood, stone, metal, and glass	0.6 to 2.1, depending on the block material	45 to 90, depending on the block material
minor sounds	A huge number of minor sounds, like the blade trap hitting something and the dart trap shooting	0.05	60

Note: Running, using non-fire-based light sources, and continuously using generators and solar banks don’t generate heat values.