Cold shock proteins (CSPs) are a group of proteins that are induced by exposure to cold temperatures. They are found in all living organisms, from bacteria to humans. CSPs play a role in protecting cells from the harmful effects of cold, such as damage to membranes and proteins. Cold shock proteins are multifunctional RNA/DNA binding proteins, characterized by the presence of one or more cold shock domains. In humans, the best characterized members of this family are denoted Y-box binding proteins, such as Y-box binding protein-1 (YB-1). Biological activities range from the regulation of transcription, splicing and translation, to the orchestration of exosome RNA content. Indeed, the secretion of YB-1 from cells via exosomes has opened the door to further potent activities. Evidence links a skewed cold shock protein expression pattern with cancer and inflammatory diseases.

CSPs are small proteins, typically ranging in size from 10 to 30 kDa. They are characterized by the presence of one or more cold shock domains (CSDs). CSDs are short, amino acid sequences that are involved in binding to nucleic acids.

Some of the cold shock proteins that have been identified in humans include:

  • CARHSP1, which stabilizes tumor necrosis factor (TNF), a protein that causes inflammation.
  • Lin28, a protein that’s been studied for its ability to reprogram cells.
  • YB-1, which may promote wound healing.


      Cold shock proteins can be activated more easily: Research suggests they can be released when you’re a little cooler than the normal body temperature of 37°C (98.6°F).

         The idea of releasing your body’s stress proteins on purpose sounds counterintuitive. Stress is often thought of as a bad thing that should be avoided. While chronic stress isn’t good for you, exposure to the right doses of certain stressors can have health benefits. This concept is known as hermetic stress.

              Hermetic stress is a level of stress that challenges your body and helps you build resiliency. Scientific research has linked this healthy stress response to a number of health benefits, from a better tolerance to stress to an increased lifespan.


            Cold shock proteins are an emerging area of scientific research, but many exciting health benefits have already been identified. These proteins may play a role in promoting muscle growth and recovery, so it’s no wonder that cold therapy is popular with athletes. Cold shock proteins may also help you maintain your muscle mass during periods of disuse. This could include when you’re too busy to make it to the gym or when you’re taking some planned time off your training routine. Some cold shock proteins are known to help decrease inflammation and support faster wound healing. That’s why cold therapy can be an effective non-pharmaceutical support for people with a variety of conditions, such as fibromyalgia and rheumatoid arthritis.

             The exact function of CSPs is not fully understood, but they are thought to play a role in a variety of cellular processes, including:

  • Protecting cells from the harmful effects of cold
  • Regulating gene expression
  • Repairing damaged proteins
  • Chaperoning newly synthesized proteins
  • Promoting cell survival

             CSPs have been shown to be beneficial in a number of different contexts. For example, they have been shown to protect cells from damage caused by chemotherapy and radiation. They have also been shown to be effective in treating a variety of diseases, including cancer, Alzheimer’s disease, and Parkinson’s disease.

               CSPs are among the most evolutionarily conserved proteins, meaning that they are found in all living organisms, from bacteria to humans. This suggests that CSPs play an essential role in cell survival.


         Unlike heat shock proteins, which are released in response to heat stress, research suggests that cold shock proteins can be activated by mild cold exposures. These proteins are produced when your body temperature dips below 37°C (98.6°F). There are many ways to lower your body temperature and activate cold shock proteins. Read on for some ideas.

  • Exercise in Cold Weather

Colder temperatures are fast approaching in many parts of the country. If you normally take your workouts indoors when temperatures drop below freezing, consider exercising outdoors this year. Ice skating, cross-country skiing, snowshoeing, or other outdoor activities can leave you feeling chilly and activate your cold shock proteins.

  • Take a Cold Shower

Cold showers are a simple way to introduce cold therapy to your life. Some people prefer to step right into the icy water, while others prefer to ease in by switching between hot and cold water during their showers. To reap the benefits of cold showers, try to stay under the cold water for at least 30 seconds.

  • Practice Cold Water Immersion

If you enjoy cold showers and are ready to take things to the next level, try cold water immersion. A cold plunge can quickly lower your body temperature and help you activate cold shock proteins. The ideal temperature for cold water immersion is around 10-15°C (50-59°F). At this temperature, you can enjoy soaking for about 5 to 10 minutes.

  • Challenge Your Body With Ice Baths

A short plunge in cold water activates your body’s healthy stress response and helps you release beneficial cold shock proteins. Ice Barrel makes it easy to add regular cold plunges to your routine.


Fat loss is rarely straightforward, because our bodies are complex. There’s a reason why no single weight-loss diet has triumphed above all others, and conditions involving hormonal imbalances, like hypothyroidism, polycystic ovary syndrome and diabetes can often complicate things further. But obesity is still a growing global health crisis that currently has a limited set of tools to address it. Thankfully, recent research has shown the potential for cold water therapy as a way to prevent and treat excessive weight gain and the conditions that are associated with it, which starts with an understanding of the types of fat humans have (yes, there’s more than one).


The differences between White Fat and Brown Fat

White fat or White Adipose Tissue (WAT)

  • The most common type of fat for adults
  • It insulates and cushions vital organs like the kidneys and the heart
  • These tissues are responsible for storing energy, and are the culprits in making us fat, adding inches to our waist and thighs
  • It lacks mitochondria, cell energy-producing centres
  • It interacts with hormones such as cortisol, the stress hormone, and insulin, the hormone which controls the amount of sugar in our bloodstream at any one moment
  • Having a lot of this type of fat is associated with heart disease, diabetes and many types of cancers

Brown fat or Brown Adipose Tissue (BAT)

  • Previously thought to only be present in mammals and human babies, to keep them warm, but discovered to be present in human adults in 2009
  • Primarily located around your neck and collar bone
  • It contains mitochondria, which makes BAT look brown under a microscope (hence the name!) because they contain iron
  • Mitochondria contain a protein called UCP1 that breaks down fat to make heat and uncouples mitochondrial respiration from ATP synthesis (in English, that means our bodies prefer to burn brown fat over white fat for heat)
  • It’s more closely related to muscle than it is to WAT, being much more vascularised with capillaries and innervated with neurons
  • Its main function is thermogenesis, creating heat to raise body temperature by burning energy

As a result, it burns through calories at quite a high rate!


       Thermogenesis and the cold stress response are the key. When we expose our body to cold, it attempts to generate more heat. It can do these one of two ways: first, our bodies begin to shiver. While shivering, our body activates tiny muscle contractions to create kinetic energy, which is then converted into heat energy. Second, our body generates heat by increasing its metabolic demand and burning up stored calories. In this case, it’s BAT that does this, in a process called cold thermogenesis.  


       Thermogenesis is a way we produce heat to keep our bodies warm. Cold thermogenesis kicks this process into overdrive. When you’re exposed to colder temperatures, your body works harder to maintain homeostasis and regulate core temperature. It produces more energy to stay warm, burning calories to produce that heat. This in turn stimulates metabolism. Hormones involved in body temperature regulation also play a role in stimulating heat-related fat breakdown, including epinephrine, norepinephrine, and thyroid hormones. In particular, exposure to the cold causes an increase in norepinephrine through upregulation of cold shock proteins – it’s the signaling molecule that ‘switches on’ BAT.

       In rodents and humans, various regimens of cold exposure have been repeatedly shown to increase BAT activation, and research has also demonstrated how activated BAT can use glucose and fatty acids as fuel for thermogenesis, enhancing overall energy expenditure in rodents and humans. In one study, a 3-hour period of cold exposure was shown to burn 250 extra calories through BAT, with the calories coming almost exclusively from WAT. Experiencing a drop in temperature also leads to stem cells reportedly making brown instead of white fat, prompting the body to burn extra calories. 


       Your metabolism is how fast your body converts food into energy. The faster and more efficient your metabolism is, the more energy you’ll likely have, and the easier you’ll find it to lose weight. Cold plunging can aid weight loss by increasing the burning of white fat (a.k.a. “bad fat”). This happens because cold exposure forces your body to rev up your metabolism and get the energy it needs for heat generation (in one study, metabolism increased 350% when participants were exposed to 14oc/57F water). It also starts to use brown fat (a.k.a. “good fat”) to convert into heat energy. The rest of the body that is using energy, unrelated to heat production, starts burning up the “bad fat” and as a result it can create accelerated weight loss. 

     Higher levels of BAT are associated with a more effective metabolism, and cold temperatures have been shown to push BAT deposits into calorie burning heat generation 25-40% higher than basal metabolic rate. One of the ways research suggests it does this, as well as increasing glucose and lipid uptake, is through mitochondrial uncoupling, resulting in elevated energy expenditure as well as increased insulin sensitivity. BAT also maintains a high oxidative metabolic capacity, and when it is highly active, it exerts beneficial metabolic effects on obesity, insulin resistance, and atherosclerosis (thickening or hardening of the arteries). 


      Our metabolism relies on hormones to keep it functioning well, particularly those from our thyroid gland. It releases two hormones: Thyroxine (T4) and Triiodothyronine (T3). When too little of these hormones are released from the thyroid (known as hypothyroidism) it can result in weight gain. Because our thyroid plays such a major role in our metabolism, if it becomes dysfunctional, it can affect almost every part of the body, including our energy levels and the ability to burn calories. Cold plunging is a potential tool for relieving the symptoms of hypothyroidism, because it has been shown to decrease TNF-a and IL-2-pro-inflammatory cytokines. By lowering these cytokines, dysfunction in the thyroid is reduced, and normal secretion of T3 and T4 can continue. In addition, cold water immersion also reduces cortisol levels that can negatively impact hormonal secretions, and lead to hypothyroidism.

       BAT and cold exposure may also play a crucial role in healing the hormonal dysfunctions that accompany obesity, in particular the hormone leptin, which is one of the most important regulators of body mass. Leptin acts like a thermostat – or in this case, an ‘adipostat’ – working hard to keep your body mass constant by increasing your appetite when your fat stores are low, and decreasing your appetite when your fat stores are high. People who carry more weight are leptin resistant: their fat mass is producing plenty of leptin, but their body isn’t listening to the leptin signaling. Leptin isn’t the problem at all – it’s the sensitivity of the leptin receptors. Cold exposure has been seen to improve leptin sensitivity, allowing the body to hear the signals again and reach a lower baseline. Research has also shown promise for cold water therapy as a way to override the ‘adipostat’ hypothesis and encourage your body to stop panicking when you lose fat.

       Another hormone that releases when you take a cold dip is adiponectin. Low adiponectin levels have been associated with obesity, diabetes and cardiovascular disease. It breaks down fat and shuttles glucose into the muscles, which can lower blood sugar. This not only has an anabolic, muscle repair effect, but it can also enhance recovery, and research has shown that it can have a ‘browning effect’ on WAT (making it function more like BAT).

      Testosterone is also a key tool in the fight to lower body fat, because of the way it regulates fat metabolism, glucose and insulin. Testosterone deficient men tend to gain fat more easily than their healthy peers, and on average, obese men have 30% lower testosterone levels than those who are a normal weight, demonstrating the significance of the relationship. When men take a cold plunge, it lowers the temperature of their scrotum, which allows the testicles to produce the maximum amount of sperm and testosterone. One study found that keeping testicular temperature between 31-37oc/88-99oF allowed for optimal DNA, RNA and protein synthesis, which results in better sperm production, and another study found that cold, winter temperatures improved sperm shape and movement. Why does it matter? Because when you improve sperm, you improve testosterone.