Snakes are cold-blooded (ectothermic) reptiles. Consequently, all species of snakes have strict temperature requirements. If a snake can’t find somewhere to warm up, or at least stop getting colder, it’ll eventually die.
When a snake gets too cold, it will seek out a basking spot. If one isn’t available, it will find shelter, e.g. a burrow. If it remains cold, the snake will regurgitate/vomit its food and stop eating. It will then become lethargic (stop moving) and could become ill, or even die.
A snake should never be kept in cold conditions. Vivarium setups for all snake species should have at least one thermometer and a heat source, e.g. a heat mat. With these in place, your snake should be warm enough.
What Happens When a Snake Gets Too Cold?
All reptiles are vulnerable to the cold. Because they can’t produce body heat, they need to get warmth from their environments instead.
When a snake gets too cold, there are many things that will happen. Your snake will alter its behavior, in part to try and get warm, and in part, because it’s limited in cold weather. This will be a noticeable change.
The cold can also have unintended effects like making your snake sick, or killing it. Here’s a table of symptoms in the likely order that you’ll see them:
|Snake is trying to get warm||Your snake will seek out a basking spot or a shelter, to warm up/avoid the cold.|
|Regurgitation or vomiting||Without warmth, a snake can’t digest. It will regurgitate any food in its throat, and vomit any food in its stomach.|
|Anorexia||Because a cold snake can’t digest, it will stop wanting to eat. Even if you offer it snacks that it loves, your pet won’t want to eat them.|
|Lethargy||A cold snake will move less than usual.|
|Sickness||If your snake is already sick, its illness will become worse. It will also become more susceptible to conditions like respiratory infections because its immune system isn’t working properly.|
|Death||The above effects will accumulate until your snake dies.|
Check the temperature that your snake should be kept at. This differs between species, because they’re from different climates.
Your Snake Will Try to Get Warm
When your snake’s environment is too cold, it will seek out warmth. If your snake’s enclosure has a basking spot, it will move towards it and stay there. It will stay there for longer than it normally does.
Snakes need to do this because they’re ectothermic. That means cold-blooded. They cannot produce even a small amount of body heat. If they can’t find a warm spot, their bodies will revert to the ambient temperature. If that temperature is freezing, then the snake will freeze.
Your snake’s enclosure should have a basking spot. You need to provide your pet with warmth, either through a heat map, heat tape, or a heat lamp. The temperature of both the basking spot and the air should be appropriate for the species of your snake.
If there isn’t a basking spot, your pet will try to avoid the cold in other ways. If your snake is a burrowing snake, then it will hide in its hide/burrow. This is an evolutionary adaptation that helps it avoid frost, rain, and snow.
This won’t warm your snake up as much as a basking spot. But it will stop your snake from getting excessively cold.
Your Snake Will Regurgitate or Vomit Its Food
If your snake is cold for an extended period of time, it will begin to experience health effects. One is that your snake can’t digest anymore.
Because snakes are ectothermic, their digestive systems aren’t as effective. In mammals, the digestive process is aided by bacteria in the gut. The bacteria break food down to make for easier digestion.
A snake has bacteria in its gut. However, these bacteria can’t break food down if the temperature is too cold. So, it will find a basking spot after eating like a hot rock. The warmth from the rock makes digestion quicker.
But in cold temperatures, your snake can’t do this. Its gut cannot digest food at all if it’s too cold. The food will rot before your pet gets the chance. As such, your pet will either regurgitate or vomit its food back up.
To be clear, there’s a difference between regurgitation and vomiting. Regurgitation is where your snake brings up food that it has only just eaten. The food will be whole and undigested. It’s brought up from the throat.
Vomited food is brought up from the stomach. Depending on how long it has been in the stomach, it may be not at all, partially, or completely digested. Both regurgitation and vomiting occur when a snake gets too cold.
Your Snake Will Stop Trying to Eat
When temperatures drop, something clicks in your snake’s instincts. It stops wanting to eat at all.
The cause of this is that any food your snake does try to eat will be regurgitated. So, your snake’s instincts tell it not to bother. Hunting would be wasted energy.
If you have ever tried to breed your snakes, you will have noticed this when your temperature cycled them. This is when you make the enclosure a little colder to simulate winter, before warming it up again for ‘spring’. This gets the snakes ready to mate. During this time, they won’t eat.
Your snake will only start trying to eat again when the temperatures rise. Or, when it gets access to a basking spot, it may eat before sitting there a while.
Your Snake Will Become Inactive
If your snake doesn’t have anywhere to warm up, it will become lethargic. In some cases, it will stop moving for extended periods of time. And when it does move, it will move slowly.
This is commonly confused with hibernation. Snakes don’t hibernate (only mammals do). It involves the body temperature dropping and the heart rate/breathing rate dropping. Snakes don’t do either of these things.
What snakes do is called brumation. This is like an extended period of rest. It’s similar to hibernation in that way, but without the heart rate slowing and the breathing rate dropping.
To brumate, the snake needs a burrow. BioOne state that this burrow is called a hibernaculum, i.e. a hibernating place.
It will then sit in the burrow hardly moving until the temperature rises again. It may occasionally move during the warmest part of the day, trying to find a sunny spot. But apart from that, it will be entirely inactive.
Snakes Get Sick in The Cold
Cold temperatures make existing health conditions worse. The main example of this occurring is with respiratory infections. A respiratory infection is like a cold, but more serious.
A snake with a respiratory infection will try to get warm, to fight it off. Warm temperatures help the body’s immune system function better.
But in cold temperatures, this isn’t possible. The snake’s immune system cannot fight the infection effectively, so it becomes even more serious. This could lead to your snake’s death.
Any health condition can be made more serious if the immune system isn’t working properly. Something mundane like mites may become a life-threatening condition.
What makes this issue even worse is that your snake won’t be eating. While temperature is important for the immune system, so is nutrition. Without adequate nutrition, your snake will become weak, and so will its immune system. This makes illnesses worse again.
Snakes Die in The Cold
Your pet could die of snake hypothermia if it’s cold for long enough. This is a cumulative effect of several issues related to the cold temperature.
In temperatures that are cold enough, organs stop working. This is the case for all animals. In mammals, this temperature is high, and is maintained by body heat. In reptiles, it’s lower, but the same dire effects will still occur if the temperature is too low.
The effect of organ failure is sudden and intense. The kidneys filter the blood to remove waste, toxins, and water. The liver does something similar. The lungs take in air and absorb oxygen. These functions, and those of the rest of the organs, are vital to life. Without them, the animal dies.
But other effects build up too. In low-level cold temperatures, the snake can’t eat. Over time, the snake could easily starve. While snakes eat less frequently than other animals, they will still starve if not fed enough. This applies both in captivity and the wild.
Lethargy also has negative effects. A snake that won’t move can’t escape from predators. So, snakes are more vulnerable when they’re lethargic.
Freeze Tolerance in Reptiles
Reptiles and other cold-blooded animals have additional tools at their disposal for resisting cold. Freeze tolerance is where the animal prepares its body so that some of its body water can freeze, but it still survives.
Several reptile species display ecologically relevant freeze tolerance, surviving for extended times with 50%+ of their total body water frozen.Cryobiology
This is something mammals can’t do because mammalian organs require higher temperatures to function.
Not all snakes can do this, but a certain few species can. Garter snakes are one species that have been found to do so. A paper by Cryo-Letters titled ‘Natural Freeze Tolerance in a Reptile’ examined the issue.
The paper states that garter snakes can survive the freezing of at least 36.2% of their body water. They can remain frozen for 48 hours without injury. They can then be ‘thawed out’ and continue as normal.
Unlike other animals that have freeze tolerance, garter snakes don’t use an antifreeze-like substance in their blood to prevent freezing. So, it’s unclear how they can survive. But they can. Garter snakes are the largest and most advanced vertebrate that can do this.
What Temperature Is Too Cold for Snakes?
The temperature at which snakes get too cold depends on the species. But snakes start to get sick at temperatures lower than 70 degrees Fahrenheit.
Snakes have spread to every continent except for Antarctica, so they live in a variety of habitats. Some live in tropical places, so need to be warm. Others live in cooler climes. As such, your snake may survive in cooler temperatures than others.
Here’s a table explaining the temperatures that snakes need:
|Species||Basking Spot Temperature||Ambient Temperature|
|Corn Snake:||85 degrees||75 degrees|
|Ball Python:||90 degrees||80 degrees|
|Boa Constrictor:||90 degrees||75 degrees|
|Hognose Snake:||88 degrees||78 degrees|
|California Kingsnake:||85 degrees||75 degrees|
|Rosy Boa:||85 degrees||75 degrees|
|Gopher Snake:||85 degrees||75 degrees|
Ball pythons need warm temperatures because they’re from North Africa. Here, around the equator, the temperature remains high throughout the year. So, ball pythons need a high ambient temperature. But corn snakes, from North America, don’t need to be kept so warm.
Can Snakes Survive in Snow?
Snakes cannot survive in snow. If your snake sits somewhere snowy and frosty for long enough, it will freeze to death.
But that doesn’t mean that snakes can’t survive in places that get snow. Many snake species live far north or south enough that they encounter snow. They avoid it by hiding in burrows.
Crucially, the snake needs to burrow deeper than the frost level. This is the level to which the soil freezes. If the snake can stay beneath the frost level, it can survive. But if it’s surrounded by frost and frozen soil, it will die.
This only applies to certain species. A tropical species like the boa constrictor can’t survive in snow. It’s used to higher temperatures and it doesn’t know how to burrow. If it encountered snow, it would die. But certain species like the timber rattlesnake can hide in burrows, and are used to cold winters.
So, a snake won’t survive if it has to sit in the snow. But it may survive in snowy areas.
At What Temperature Do Snakes Become Inactive?
Snakes that brumate do so at about 60 degrees. Owners and breeders suggest a temperature of 55 degrees for brumating corn snakes, for example.
But the temperature at which a snake becomes inactive depends on its species. Tropical snakes will do so sooner than hardy snakes used to colder climates. A temperature this low would kill a ball python.
Can Snakes Survive in Cold Water?
Snakes can’t survive cold weather easily. The problem is even worse if they encounter cold water.
That’s because being in cold water ‘feels’ colder than being in cold air. Water is a better carrier of heat than air. So, an animal’s body heat seeps out into water quicker than it does into the air of the same temperature.
This cools the animal down faster, which means that a snake can quickly die in cold water. There are snakes that live in water, i.e. water snakes. But these don’t permanently live in water. They spend most of their time on the riverbank instead.
There are sea snakes that spend their entire lives in water. But these snakes are specially adapted to the sea, and can survive lower temperatures more easily.
This applies to captivity, too. A snake should never sit in a pool of water, cold or otherwise. If it does, it will develop scale rot.
Do Snakes Experience Cold Shock Response?
Cold shock syndrome/the cold shock response is the response of an animal to falling into cold water. The shock of the icy cold makes an animal involuntarily inhale a large amount of air. But in water, this is problematic, because it causes the inhalation of water.
This response hasn’t yet been demonstrated in reptiles. That doesn’t ‘prove’ that reptiles don’t have this same response, but it’s likely that they don’t.
Either way, this isn’t what will kill a snake if it falls into the water. What will kill it is the temperature. But your snake shouldn’t encounter ice-cold water in its enclosure anyway.
Your snake’s cage should be fitted with two thermometers. One should be placed on the basking spot, and one should measure ambient air temperature. If you notice that the temperature of either of these two thermometers show is too low, correct the issue immediately.