Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+ and hydroxide anions OH−.
Dry ice colloquially means the solid form of carbon dioxide. It is commonly used for temporary refrigeration as CO2 does not have a liquid state at normal atmospheric pressure and sublimes directly from the solid state to the gas state. It is used primarily as a cooling agent, but is also used in fog machines at theatres for dramatic effects. Its advantages include lower temperature than that of water ice and not leaving any residue (other than incidental frost from moisture in the atmosphere). It is useful for preserving frozen foods (such as ice cream) where mechanical cooling is unavailable.
Keloid, also known as keloid disorder and keloidal scar, is the formation of a type of scar which, depending on its maturity, is composed mainly of either type III (early) or type I (late) collagen. It is a result of an overgrowth of granulation tissue at the site of a healed skin injury which is then slowly replaced by collagen type I. Keloids are firm, rubbery lesions or shiny, fibrous nodules, and can vary from pink to the color of the person's skin or red to dark brown in color. A keloid scar is benign and not contagious, but sometimes accompanied by severe itchiness, pain, and changes in texture. In severe cases, it can affect movement of skin. In the United States, keloid scars are seen 15 times more frequently in people of sub-Saharan African descent than in people of European descent. There is a higher tendency to develop a keloid among those with a family history of keloids and people between the ages of 10 and 30 years.
Frostbite is a skin injury that occurs when someone is exposed to extremely low temperatures, causing the freezing of the skin or other tissues, commonly affecting the fingers, toes, nose, ears, cheeks and chin areas. Most often, frostbite occurs in the hands and feet. The initial symptoms are typically a feeling of cold and tingling or numbing. This may be followed by clumsiness with a white or bluish color to the skin. Swelling or blistering may occur following treatment. Complications may include hypothermia or compartment syndrome.
Chilblains, also known as pernio, is a medical condition in which damage occurs to capillary beds in the skin, most often in the hands or feet, when blood perfuses into the nearby tissue, resulting in redness, itching, inflammation, and possibly blisters.
Fractional freezing is a process used in process engineering and chemistry to separate substances with different melting points. It can be done by partial melting of a solid, for example in zone refining of silicon or metals, or by partial crystallization of a liquid, as in freeze distillation, also called normal freezing or progressive freezing. The initial sample is thus fractionated.
Thermal energy storage (TES) is the storage of thermal energy for later reuse. Employing widely different technologies, it allows surplus thermal energy to be stored for hours, days, or months. Scale both of storage and use vary from small to large – from individual processes to district, town, or region. Usage examples are the balancing of energy demand between daytime and nighttime, storing summer heat for winter heating, or winter cold for summer cooling. Storage media include water or ice-slush tanks, masses of native earth or bedrock accessed with heat exchangers by means of boreholes, deep aquifers contained between impermeable strata; shallow, lined pits filled with gravel and water and insulated at the top, as well as eutectic solutions and phase-change materials.
Outdoor recreation, such as hiking, camping, canoeing, cycling, or skiing, entails risks, even if participants do not recklessly place themselves in harm's way. In some circumstances, such as being in remote locations or in extreme weather conditions, even a minor accident may create a dangerous situation that requires survival skills. However, with correct precautions, even fairly adventurous outdoor recreation can be enjoyable and safe.
Cold compression therapy, also known as hilotherapy, combines two of the principles of rest, ice, compression, elevation to reduce pain and swelling from a sports or activity injury to soft tissues and is recommended by orthopedic surgeons following surgery. The therapy is especially useful for sprains, strains, pulled muscles and pulled ligaments.
A frigorific mixture is a mixture of two or more phases in a chemical system that, so long as none of the phases are completely consumed during equilibration, reaches an equilibrium temperature that is independent of the starting temperature of the phases before they are mixed. The equilibrium temperature is also independent of the quantities of the phases used as long as sufficient amounts of each are present to reach equilibrium without consuming one or more.
Throat irritation can refer to a dry cough, a scratchy feeling at the back of the throat, a sensation of a lumpy feeling, something stuck at the back of the throat, or possibly a feeling of dust in the throat. The symptoms are unpleasant and usually temporary, but occasionally signifies a more serious health issue, such as laryngitis.
Cold injury is damage to the body from cold exposure, including hypothermia and several skin injuries. Cold-related skin injuries are categorized into freezing and nonfreezing cold injuries. Freezing cold injuries involve tissue damage when exposed to temperatures below freezing. Nonfreezing cold injuries involve tissue damage when exposed to temperatures often between 0-15 degrees Celsius for extended periods of time. While these injuries have disproportionally affected military members, recreational winter activities have also increased the risk and incidence within civilian populations. Additional risk factors include homelessness, inadequate or wet clothing, alcohol abuse or tobacco abuse, and pre-existing medical conditions that impair blood flow.
The cinnamon challenge is a food challenge that gained viral recognition on social media in the early 2010s. Participants generally film themselves attempting to eat a spoonful of ground cinnamon in under 60 seconds without drinking anything. The challenge is difficult and carries substantial health risks because the cinnamon can coat and dry the mouth and throat, possibly resulting in coughing, gagging, vomiting, and inhalation of cinnamon, which can in turn lead to throat irritation, breathing difficulties, and risk of pneumonia or a collapsed lung.
An aerosol frostbite of the skin is an injury to the body caused by the pressurized gas within an aerosol spray cooling quickly, with the sudden drop in temperature sufficient to cause frostbite to the applied area. Medical studies have noted an increase of this practice, known as "frosting", in pediatric and teenage patients.
The condom challenges are two viral Internet challenges. The first is a challenge involving snorting a latex condom through one's nasal cavity and into the back of the throat; the second is a challenge where a water-filled condom is dropped onto a person's head, typically enveloping the head of the person taking part. Both variations carry a risk of choking and suffocating.
The fire challenge is an internet challenge which involves applying flammable liquids to one's body and then setting the liquids aflame, while being video recorded; the footage is then posted to social media sites. Firefighters, police officers and media sources have criticized and spoken out against the activity, hoping to dissuade individuals from trying it due to its harmful nature.
The Ice Bucket Challenge, sometimes called the ALS Ice Bucket Challenge, was an activity involving the pouring of a bucket of ice water over a person's head, either by another person or self-administered, to promote awareness of the disease amyotrophic lateral sclerosis and encourage donations to research. The challenge was co-founded by Pat Quinn and Pete Frates; it went viral on social media during July–August 2014. In the United States, many people participated for the ALS Association, and in the United Kingdom, many people participated for the Motor Neurone Disease Association, although some individuals opted to donate their money from the Ice Bucket Challenge to other organizations.
Like most detergent products, Tide Pods, a laundry detergent pod sold by Procter & Gamble (P&G) since 2012, can be deadly if ingested. Media reports have discussed how children and those with dementia could mistake laundry pods for candy and endanger their health or life by consuming them, and they were named an emerging health risk by the Centers for Disease Control and Prevention in 2012. Between 2012 and 2013, poison control centers reported over 7,000 cases of young children eating laundry pods, and ingestion of laundry pods produced by P&G had resulted in six deaths by 2017. In response to the dangers, P&G changed Tide Pod containers to an opaque design, introduced warning labels, and added a bitter-tasting chemical to the pod contents.
Non-freezing cold injuries (NFCI) is a class of tissue damage caused by sustained exposure to low temperature without actual freezing. There are several forms of NFCI, and the common names may refer to the circumstances in which they commonly occur or were first described, such as trench foot, which was named after its association with trench warfare. NFCI is caused by microvascular endothelial damage, stasis and vascular occlusion and is characterised by peripheral neuropathy. NFCI generally affects the hands or feet during exposure to temperatures just above freezing, often wet, and is typically found in soldiers.
