Quarantine Zone: The Last Check Guide – How to Unlock All Symptoms

How to identify symptoms in the laboratory

If you detect a symptom you’re unfamiliar with, you can refer the victim to the lab. Follow the survivor there and wait for them to be strapped into the apparatus inside the glass dome. Then, access the nearby computer. This will launch a minigame in which you control a laser. The W and S keys raise and lower the aiming circle. The A and D keys rotate the cursor around the survivor (or, if you prefer, the test subject themselves). The mouse controls the pointer, which is linked to the aiming circle. When the mouse cursor selects a muscle, bone, or organ, it turns orange, red, or green.

An object that can be destroyed with a laser by holding down the left mouse button is marked in orange.
The red color indicates an item that should not be destroyed, since too frequent destruction of such organs, bones, muscles can lead to failure of the entire mini-game.
The item highlighted in green is the one that needs to be retrieved by holding down the E key instead of left-clicking (but only when it is completely highlighted in green).

Use a combination of rotation and obstacle destruction to open your line of sight and reach the green item. After extraction, the survivor falls dead, and shockingly, destroying multiple internal structures and organs with a laser isn’t exactly conducive to survival, but if they weren’t infected, you won’t be penalized for it. The extracted organ will appear in a crate to your left. Pick it up and throw it into the machine next to the crate, then press E to convert it into a vial/sample. Place the vial in the analyzer on the table slightly to the right and press E again to detect a new symptom, if one existed initially and if you didn’t have it in your symptom card. Tip : You can extract whatever you want, but only one item per survivor. Extracting the brain can be used to earn a secret achievement. To do this, you’ll need to take it to the living quarters and throw it through the basketball hoop.

When will the lab open?

During the first few hours of play, around the fourth or fifth day, the game will throw you a curveball—a symptom not yet on your list. At this point, the system automatically highlights it and launches a tutorial scene, so you can’t miss this new feature. However, things become much less obvious: the appearance of further unknown symptoms is no longer highlighted. You’ll have to identify them yourself. The general rule is simple: if you notice something unusual, something you haven’t encountered before and that isn’t on your symptom list, there’s a high probability you’re dealing with a new symptom. As the tutorial explains, to study an unknown symptom, you need to send the patient to the Lab. There, you’ll play a minigame in which you extract an organ highlighted in green. After that, all that’s left to do is place the extracted organ in the appropriate analyzer and complete the study.

Symptom scanner

With subsequent base upgrades, you’ll be able to upgrade the metal detector at the entrance (checkpoint) to detect symptoms. This will add a series of indicators on the scanner, each corresponding to a specific type of symptom. For example, a heart symbol corresponds to a thermopulse monitor . When a survivor passes by, a series of icons may light up and remain illuminated until you determine their fate (by sending them to the survivor bay, quarantine, or elimination). If a symbol lights up, it may indicate that the survivor is exhibiting one or more symptoms from that category, but they may also be missing any of them, which is a false positive. For example, the “heart” icon is illuminated, but the thermopulse monitor shows normal blood pressure and temperature. However, if the icon is off, it means that the survivor doesn’t need to be checked for that category (for example, if the “heart” icon is off, you don’t need to use the thermopulse monitor). For example, if the appearance change symbol (the “human” icon) lights up, the survivor may experience a change in eye color, a skin rash, and a nosebleed. They may also show no symptoms at all (often, in this case, survivors have white spots on their skin that are not related to any symptoms). If the thermo-pulsometer indicator lights up, this could indicate a high temperature and a rapid heartbeat, or, conversely, the temperature and pulse may be green, and the person will be fine and can be considered healthy (if other indicators are also normal). Important! If any symbol is not illuminated, it means the victim does not have symptoms in that category, and you can safely ignore checking them. Example : If the symptom indicator does not light up, there is no need to even examine them or use the scanner to check them, as they will not have any symptoms related to that category. If no symbols are lit, you can do nothing at all and immediately send the person to the survivors’ block. Note : The checkpoint scanner malfunctioned only once; when it detected a hidden UV indicator, the symbol didn’t light up. However, since this only happened once during my entire test, I think you can judge for yourself how trustworthy I am with the scanner.

Symptom severity assessment

Symptoms are classified into three colors depending on the degree of danger:

Having “green” symptoms is safe, and a survivor does not need to be quarantined or terminated for exhibiting them. Even a survivor with ten different “green” symptoms can be safely admitted to the survivor pool.
Orange symptoms are dangerous, but they don’t guarantee they’re caused by the zombie virus. A survivor with a single orange symptom may turn into a zombie, or they may recover. It’s best to isolate any survivor with orange symptoms and check daily to see if their symptoms are improving or worsening. If they improve or disappear, send them to the survivors’ block; if they worsen or remain unchanged, it’s best to eliminate them. Also, most survivors turn into zombies by the third day of quarantine, so if they can survive that long without turning into a zombie, they’ll be fine. And be careful not to place a group of survivors together with someone who’s already been quarantined for a day, as if they turn into a zombie (which will happen faster if they’re infected), they’ll wipe out all the survivors in the quarantine chamber.
Red symptoms are symptoms of the zombie virus. If a survivor has even one red symptom, they must be eliminated. There’s no reason to quarantine them, as these symptoms won’t improve. And if they’re allowed into a residential unit, they’ll later turn into zombies and kill at least one person per night.

Objects

This set of symptoms applies to survivors who bring a backpack; you can open the backpack and see its contents, which will be displayed on a table near the exploration area. These symptoms don’t need to be noted for the check to be considered excellent. Most of them don’t count as symptoms and shouldn’t influence decisions about where the survivor goes unless a side quest specifies otherwise.

These symptoms don’t trigger the Symptom Scanner, but there are separate scanner upgrades that allow the detection of backpacks containing weapons, drugs, and zombie parts when a survivor passes through them. Note that, unlike the Symptom Scanner, these indicators only flash briefly and turn off after a few seconds.

Option 1 – Baggage

This only means that the survivor brought a backpack with him.

Option 2 – Weapons

This means a survivor is attempting to smuggle contraband. This could be weapons, ammunition, or drugs (like a syringe). You can confiscate any of these items, earning $100 for each. But be careful, as confiscating the wrong item will also result in a $100 fine. Some drugs are prescription medications, which, as far as I understand, aren’t considered contraband. Tip : If you confiscate gas, food, or medication, you’ll still lose $100, but these items will be added to your storage as essential resources for running and maintaining your base. The game indicates this, but I’ve never tested it because a $100 fine is much more than buying the necessary supplies (food or first aid kits) the normal way.

Option 3 – Contaminated baggage

Red infection symbol

It manifests as any bloody human body parts. These can include limbs, fingers, heads, bones, organs, and so on. A survivor is considered infected simply by the presence of these parts in their backpack, regardless of other symptoms, and must be eliminated. Note : Some survivors bring with them a pile of human teeth arranged in a semicircle; for some reason, these do not count as infected baggage. Tip : Repossessing these items costs $10 because you are not allowed to touch them, but doing so will earn you the achievement .

Option 4 – Internal smuggling

Items appear hidden inside a survivor’s organs when using the X-ray machine. Hover over the item and press E. Then exit X-ray mode and talk to Charlie, the man in the white hazmat suit. He will retrieve all marked items and place them on his small tray for confiscation if they are contraband. Tip : Items can be found in the lower half of the intestines, stomach, esophagus, or mouth. Note : These items may be infected body parts. I found a severed finger on one survivor… In any case, confiscating the finger will give you a $10 fine for zombie contraband, so presumably the person carrying this item should be considered infected. Note : At the time of writing this guide, there is a bug where all internal items do not show up on the X-ray at all. When you hover over an item, a key prompt with the E key lights up, allowing you to interact with it and retrieve it as usual. Simply check the person’s entire torso and move the device around to see if the key lights up. Repeat this until it stops lighting up to ensure you’ve retrieved all the contraband, as failure to do so will result in a $100 fine.

Appearance – Eyes

The “Appearance” tab in the “Symptoms” section contains quite a few symptoms, so we’ll break it down into several categories. You can use the scanning tool to see through a survivor’s clothing, and the flashlight to illuminate the viewing area if it’s dark.

External signs: Eye symptoms are associated with a change in the color of the victim’s eyes.

Option 1 – Yellow eyes

Green symbol of disease

This manifests itself as the whites of the survivor’s eyes turning bright yellow. Tip : When using a maternity scope, the entire inner part of the eye will also appear yellow.

Option 2 – Conjunctivitis

Orange symbol of disease or infection, survival questionable

Symptoms include redness in the corners of the eyes, which may appear swollen or cloudy. Advice : When using a matioscope, there will be no visible changes inside the eye. This allows one to determine whether the eye is simply conjunctivitis or simply redness. Note : It is possible that one of the surviving patients will simultaneously have discolored whites of the eyes and conjunctivitis. If the disease is too advanced to use a matioscope to check eye color internally, pay special attention to the small amount of white that can still be seen.

Option 3 – Red Eyes

Red infection symbol

It manifests as redness of the whites of the survivor’s eyes. Tip : When using a maternity scope, the entire inside of the eye will appear red.

Appearance – Skin Markings

Skin tags are marks on the skin, either natural or caused by injury or disease. They can appear anywhere on the skin, even under clothing and in hard-to-reach areas such as the feet, arms, or sides behind the arms.

Option 1 – Freckles

Green symbol of disease

It appears as a large number of small, usually brown or orange, spots on the survivor’s face, cheeks and nose.

Option 2 – Herpes

Green symbol of disease

It needs to be unblocked in a lab. It appears as a rash of small, irregularly shaped spots, usually brown or red, without any pimples.

Option 3 – Bruises

Green symbol of disease

It appears as one large or several medium-sized spots, usually a mixture of blue, green and yellow.

Option 4 – Skin rash

Orange symbol of disease or infection, survival questionable

It needs to be unblocked in a lab. It appears as a rash consisting of multiple pimples and whiteheads, as well as very small spots around the pimples. Inflamed, watery blisters.

Option 5 – Skin cuts

Orange symbol of disease or infection, survival questionable

Appears as one large spot, often lighter than the surrounding skin, with many barely noticeable or thick scratches within the spot.

Option 6 – Bruise

Orange symbol of disease or infection, survival questionable

It looks like several dark red spots.

Option 7 – Necrosis

Red infection symbol

Appears as multiple dark black spots. Advice: Be careful not to confuse tattoos with skin designs. Especially avoid mistaking them for necrosis or necrotizing skin lesions, as many tattoos are done in black ink. Look for obvious artistic and artificial designs, such as faces, wings, recognizable symbols, or words, to determine whether something is a tattoo.

Option 8 – Bite mark

Red infection symbol

It looks like a set of bloody human teeth marks. There are no animal bites in this game. Every bite you see is a zombie bite. Tip : Some survivors have vitiligo, a condition in which darker skin begins to lose melanin, taking on an uneven white hue. This isn’t a symptom, but it can help identify people on the notice board (quests) or in side quests.

Appearance – Skin Color

As it may seem obvious, “skin color” refers to the abnormal coloring of the victim’s skin.

Option 1 – Red Leather

Green symbol of disease

It appears as a reddening or flushing of the skin only on the survivor’s face. It may affect only the cheeks or the entire face.

Option 2 – Pale skin

Orange symbol of disease or infection, survival questionable

It seems that the skin of every survivor appears either completely gray or simply discolored. For example, in dark-skinned people, it appears gray.

Option 3 – Green (yellow) skin

Red infection symbol

This manifests itself as the survivor’s entire skin taking on a green or very yellow tint. Tip : Pressing the Tab key will open the survivor’s file, including a photo of their normal face. This image can be used to compare with their current skin tone and spot differences.

Appearance – Face

The “Face” parameter includes features localized on the face that are not skin marks, such as discharge or facial expressions.

Option 1 – Nosebleed

Green symbol of disease

It looks like two streams of blood, one from each nostril. It’s difficult to notice if the survivor has a mustache.

Option 2 – Bleeding from the mouth

Orange symbol of disease or infection, survival questionable

It must be unlocked in the lab. It manifests as profuse bleeding covering the lower lip and running down to the chin. It’s difficult to notice if the survivor has a beard.

Option 3 – Aggression

Orange symbol of disease or infection, survival questionable

Visually, this survivor has an angry expression, often insulting the player when interacting with them. Tip : Aggressive survivors are more likely to attack the player if they are quarantined or eliminated, so keep your pistol at the ready before making a verdict.

Option 4 – Pus from the eyes

Red infection symbol

It needs to be cleared in a lab. It appears as a small drop of green pus in the corner of one eye (may be visible in both eyes). It can be very small and difficult to see, especially on certain skin tones.

Option 5 – Pus in the nose

Red infection symbol

It needs to be cleared in a lab. It appears as a drop of green pus from one nostril, usually quite noticeable and easily visible, although, again, it can be difficult to see due to the mustache.

Thermopulsometer

A thermopulsometer is a device that measures the heart rate and temperature of a person who has survived the illness. Symptoms are determined by how much these readings exceed the normal range. There are no symptoms in this category marked green, so there’s no need to report anything if the readings are normal.Note : You can use different units of measurement—either degrees Celsius or degrees Fahrenheit (although this is unusual). For exact readings, see the list of symptoms! Tip : The temperature rises within a few seconds, so don’t take the first reading you see. Hold the device until the temperature stops rising and stabilizes. At first, everything will be fine, but then the temperature may quickly rise above the red zone. At the same time, the pulse will immediately return to the person’s normal range, meaning there’s no need to pay attention to it anymore. Note : A person who has survived the illness and has the following symptoms may also experience coughing, sneezing, and/or hiccups.

Option 1 – Elevated temperature

Orange symbol of disease or infection, survival questionable

It manifests as an increase in body temperature above normal, but still consistent with a fever. It ranges from 37 to 41 degrees Celsius.

Option 2 – Increased heart rate

Orange symbol of disease or infection, survival questionable

It manifests itself as a pulse in the range of 120 to 180 beats per minute.

Option 3 – High temperature

Red infection symbol

It manifests itself as temperatures exceeding typical human values, exceeding 42 degrees Celsius.

Option 4 – Extreme Impulse

Red infection symbol

It manifests itself as an increased heart rate of more than 180 beats per minute.

Stethoscope

A stethoscope is an instrument used to check the respiratory function of a trauma survivor. When using a stethoscope, you’ll see the victim’s lungs and several black spots. Point the stethoscope at the black spot and listen to the breathing to identify the symptom.

Note : A person who has survived the illness and has the following symptoms may also experience coughing, sneezing, and/or hiccups. Tip : Only report the most severe symptom. Do not report the symptom highlighted in green, even if you can hear it. Report only the symptoms highlighted in orange and red.

Option 1 – Painful breathing

Green symbol of disease

It sounds like breathing with a slight wheeze.

Option 2 – Non-specific breathing

Orange symbol of disease or infection, survival questionable

It needs to be unblocked in the lab. It sounds like a loud wheezing and gurgling sound. Only when inhaling. Nothing on exhalation.

Option 3 – Infected breath

It needs to be unlocked in the lab. It sounds more like a zombie’s growl than normal breathing. You can hear it on both inhalation and exhalation.

Hammer

A medical hammer used to test reflexes in survivors.

Tip : Aim for the victim’s forearms and deliver a couple of blows to elicit the most noticeable reaction. Their arm will deflect a significant distance from the blow. If this happens, there will be no symptoms. Note : The blow will leave a slight bruise at this site; keep this in mind and do not single it out as a separate symptom. Tip : People experiencing one of these symptoms will notice an open mouth and a slack jaw. If the mouth is not open, there is no need to use a hammer.

Option 1 – No reflex

Green symbol of disease

It manifests itself in the fact that the survivor’s hand barely moves, twitches slightly, about an inch, but does not make any movement no matter how many times you hit it.

Option 2 – Aggressive reflex

Orange symbol of disease or infection, survival questionable

When hit, this effect appears as if the survivor is slashing with a clawed hand. Note that if you’re close, the attack will damage you, so be careful.

Option 3 – Cross reflex

Red infection symbol

This manifests itself in the reaction occurring on the survivor’s opposite limb: if you hit their right hand, the left one will twitch instead. Note : Some have reported encountering hyper-aggressive survivors who also exhibited cross-reflexes. In this case, they strike with the hand opposite the one you hit them with. Others dispute this possibility, but keep it in mind just in case. Tip : Hit a survivor in the head to knock them down and earn the achievement . You can also hit male survivors in a different, well-known spot to get an alternative reaction. Neither of these actions has a downside unless you upgrade the hammer through the tablet. In that case, be careful when using it.

Mathioscope

A matioscope is a device that allows you to look inside a survivor’s eyeball and look for small parasites.Tip : Typically, zooming out as much as possible immediately by scrolling the mouse wheel up is enough to get a good look at everything inside the eye. However, some images may be blurry. Tip : People who have experienced the disease and have these symptoms often have closed and drooping eyelids. This makes it significantly more difficult to check the appearance of the eyes, but please refer to the tips in the “Appearance – Eyes” section for information on how a matioscope can help you check for these symptoms.

Option 1 – Lance-shaped bacterium

Green symbol of disease

It looks like a pink or slightly orange tube with branches floating in the eye, sometimes twisting.

Option 2 – Thread-like thrombus

Green symbol of disease

It looks like a bunch of white threads in the eye and remains motionless.

Option 3 – Eye helminth

Green symbol of disease

It looks like a small translucent worm wriggling in a straight line through the eye.

Option 4 – Adenovirus Bodies

Green symbol of disease

It looks like a greenish-orange ball with long tubercles, sometimes pulsating.

Option 5 – Bacteriophage

Orange symbol of disease or infection, survival questionable

It looks like a cylindrical head on tiny legs, floating in a straight line through the eye.

Option 6 – Staphylococcus aureus

Orange symbol of disease or infection, survival questionable

It appears as a blurry spot of a greenish-yellow substance that has a wave-like shape.

Option 7 – Retinal necrosis

Red infection symbol

It appears as a dark, black, blurry spot, usually roughly diamond-shaped.

Option 8 – Horny infiltrate

Red infection symbol

It appears as a dull green ball with small brown bumps. Tip : Most survivors with these symptoms will have quite a few of them, and sometimes one will appear only in the lower layer of the eye, so be sure to look for any floating particles. Note : Sometimes these small growths may be a different color than the one described or pictured in the symptom log, but their shape is important. For example, a pink growth with an orange tint or an adenovirus growth with a red tint are the same symptom as before.

X-ray

The X-ray tool, held down by the left mouse button, allows you to examine a survivor’s organs. You can scroll through the list to switch layers and limit the view to specific organs.Note : The liver is only visible in the base layer, and the brain is only visible in the third, bottom layer. Tip : People experiencing these symptoms may sometimes experience abdominal tension and a forward lean.

Option 1 – Internal bleeding

Green symbol of disease

It appears as an organ of normal reddish color, but covered with bleeding ulcers.

Option 2 – Fatty hepatosis

Green symbol of disease

It needs to be unblocked in the lab. It appears as an organ covered in yellow spots. Note : The pancreas, located behind the intestines, is always yellow and is not an organ that requires monitoring for symptoms.

Option 3 – Another color

Orange symbol of disease or infection, survival questionable

It needs to be unblocked in the lab. It appears as a normal purple or slightly pinkish-purple colored organ.

Option 4 – Mold on the organ

Red infection symbol

It needs to be unlocked in the lab. It looks like a turquoise-blue organ.

Option 5 – Organ necrosis

Red infection symbol

Must be unlocked in the Lab. It looks like an organ, almost completely covered in dark, black spots. Note : I encountered a bug where I had to unlock this item twice in the Lab. This bug may be fixed later. However, if you try to unlock it and instead see a screen stating something has been unlocked but nothing is displayed, it means you need to unlock Organ Necrosis a second time. Tip : Survivors may experience various symptoms affecting multiple organs.

UV tower

The Ultraviolet Tower is a tool that attaches to your desk (unlike other tools, which are permanently stored in your inventory). Press the button to illuminate the area with ultraviolet light. The effect lasts for a few seconds and requires a recharge, but it can be used as many times as you like.

Option 1 – UV steam

Green symbol of disease

When exposed to ultraviolet light, a greenish mist appears around part of the survivor’s body. Note : Some survivors experience a fly-like buzzing effect, although this doesn’t guarantee a result; I’ve often observed this symptom in them as well. I’m not sure if there’s a correlation, but the fly-like buzzing doesn’t seem to indicate anything else.

Option 2 – Smuggling (ultraviolet)

Red infection symbol

When exposed to active UV radiation, it appears as a green glowing spot on any item in a survivor’s backpack. Tip : Don’t confiscate contraband until you’ve checked it for UV spots!

Option 3 – Symptom (ultraviolet)

Red infection symbol

It appears as a red spot that is usually invisible, but glows green when the survivor’s body is exposed to ultraviolet light. Note : I have observed bites, necrosis, and discharge from the eyes/mouth appearing as symptoms related to ultraviolet radiation, although other symptoms are possible. However, without ultraviolet light, these symptoms are not visible.