question: why skin burns after being in a hot tub followed by jumping in the snow then back to the hot tub?
comment: Your skin is reacting to sudden extreme changes in temperature. As you haven't evolved to deal with that, this can cause pain, like a burning sensation, as well as physical damage to the skin.
passages: The form of injury is freezing of the skin, a type of frostbite. It is highly advised for those who suffer from frostbite to seek medical attention.
  
  In rare cases aerosol-induced burns can be severe enough to necessitate skin grafting.
  
  Section::::Signs and symptoms.
   Depending on the duration of exposure aerosol-induced frostbite can vary in depth. Most injuries of this type only affect the epidermis, the outermost layer of skin. However, if contact with the aerosol is prolonged the skin will freeze further and deeper layers of tissue will be affected, causing a more serious burn that reaches the dermis, destroys nerves, and increases the risk of infection and scarring . When the skin thaws, pain and severe discomfort can occur in the affected area. There may be a smell of aerosol products such as deodorant around the affected area, the injury may itch or be painful, the skin may freeze and become hardened, blisters may form on the area, and the flesh can become red and swollen.
   BULLET::::- "The Eagle" (2011). When filming in a freezing river, actors have a mixture of boiling hot water and river water poured down their suits to stay warm. A crew member forgot to mix the hot water with the river water during filming; as a result, Channing Tatum was scalded with boiling water that burned the skin off the tip of his penis.
   BULLET::::- Chilblains: condition caused by repeated exposure of skin to temperatures just above freezing. The cold causes damage to small blood vessels in the skin. This damage is permanent and the redness and itching will return with additional exposure. The redness and itching typically occurs on cheeks, ears, fingers, and toes.
  
  BULLET::::- Frostbite: the freezing and destruction of tissue
  
  BULLET::::- Frostnip: a superficial cooling of tissues without cellular destruction
  
  BULLET::::- Trench foot or immersion foot: a condition caused by repetitive exposure to water at non-freezing temperatures
   A person can cause frostbite by accidental prolonged contact, using an aerosol on one place for too long. This is often done with deodorants, but other products such as asthma inhalers are also common causes of injury. Injuries are especially common with younger children who "try it out" not knowing all the possible dermatological effects. In rarer cases aerosol burns are reported to have been caused by air fresheners and other compressed aerosol canisters exploding.
  
  Section::::Causes.:Intentional and Abuse.
   Fire play is usually considered a form of edge play - frequently exciting, but with significant dangers. Unlike other forms of edge play (extreme rough body play, blood play, interrogations, abductions, etc.), fire play scenes tend to look kinder and gentler; although it can be dramatic, the sensations inflicted in most fire play scenes aren't actually painful (much like hot wax play or sensation play). Fire play also rarely leaves marks on the skin - though some people deliberately burn the skin slightly to leave it red and irritated.
  
  Section::::Variants of temperature play.:Fire play.:Bouncing/Streaking.
   Tissue loss and autoamputation are potential consequences of frostbite. Permanent nerve damage including loss of feeling can occur. It can take several weeks to know what parts of the tissue will survive. Time of exposure to cold is more predictive of lasting injury than temperature the individual was exposed to. The classification system of grades, based on the tissue response to initial rewarming and other factors is designed to predict degree of longterm recovery.
  
  Section::::Prognosis.:Grades.
  
  Grade 1: if there is no initial lesion on the area, no amputation or lasting effects are expected
   At temperatures greater than , proteins begin losing their three-dimensional shape and start breaking down. This results in cell and tissue damage. Many of the direct health effects of a burn are secondary to disruption in the normal functioning of the skin. They include disruption of the skin's sensation, ability to prevent water loss through evaporation, and ability to control body temperature. Disruption of cell membranes causes cells to lose potassium to the spaces outside the cell and to take up water and sodium.
   Section::::Types.
  
  Cold urticaria may be divided into the following types:
  
  Section::::Types.:Primary cold contact urticaria.
  
  Primary cold contact urticaria is a cutaneous condition characterized by wheals, and occurs in rainy, windy weather, and after swimming in cold water and after contact with cold objects, including ice cubes.
  
  Section::::Types.:Secondary cold contact urticaria.
  
  Secondary cold contact urticaria is a cutaneous condition characterized by wheals, due to serum abnormalities such as cryoglobulinemia or cryofibrinogenemia are extremely rare, and are then associated with other manifestations such as Raynaud's phenomenon or purpura.
  
  Section::::Types.:Reflex cold urticaria.
   The most widely available types of heated clothing are products for the extremities; the hands and feet. These parts are the most likely to suffer frostbite or frostnip in severe cold. As such, many manufacturers make heated gloves, mittens, socks, and boot liners, which can be purchased at workers' supply stores (serving construction workers) and motor sports stores. Heated torso coverings like vests, jackets, or leggings are available from specialty retailers that cater to motorcyclists and downhill skiers.
   If clothing the person wears catches fire, third-degree burn can develop in the matter of just few seconds.
  
  Section::::Causes.:Hot objects.
  
  Solid objects that are hot can also cause contact burns, especially by children who intentionally touch things that they are unaware are too hot to touch. Such burns imprinted on the skin usually form a pattern that resembles the object. Sources of burns from solid objects include ashes and coal, irons, soldering equipment, frying pans and pots, oven containers, light bulbs, and exhaust pipes.
  
  Section::::Prevention.
   Areas that are usually affected include cheeks, ears, nose and fingers and toes. Frostbite is often preceded by frostnip. The symptoms of frostbite progress with prolonged exposure to cold. Historically, frostbite has been classified by degrees according to skin and sensation changes, similar to burn classifications. However, the degrees do not correspond to the amount of long term damage. A simplification of this system of classification is superficial (first or second degree) or deep injury (third or fourth degree).
  
  Section::::Signs and symptoms.:First degree.
  
  BULLET::::- First degree frostbite is superficial, surface skin damage that is usually not permanent.
   There have been reports of infectious disease found in hot bodies of water worldwide, such as various "Naegleria" species. While studies have found the presence of "Naegleria" in hot spring waters, the worrisome "Naegleria fowleri" amoeba has not been identified. Nevertheless, fewer than five cases have been seen historically in Japan, although not conclusively linked to onsen exposure.
   The process of frostbite differs from the process of non-freezing cold injury (NFCI). In NFCI, temperature in the tissue decreases gradually. This slower temperature decrease allows the body to try to compensate through alternating cycles of closing and opening blood vessels (vasoconstriction and vasodilation). If this process continues, inflammatory mast cells act in the area. Small clots (microthrombi) form and can cut off blood to the affected area (known as ischemia) and damage nerve fibers. Rewarming causes a series of inflammatory chemicals such as prostaglandins to increase localized clotting.
  
  Section::::Mechanism.:Pathophysiology.
   BULLET::::- Repeated application of hot water bottles, heating blankets or heat pads to treat chronic pain—e.g., chronic backache.
  
  BULLET::::- Repeated exposure to heated car seats, space heaters, or fireplaces. Repeated or prolonged exposure to a heater is a common cause of this condition in elderly individuals.
  
  BULLET::::- Occupational hazards of silversmiths and jewellers (face exposed to heat), bakers and chefs (arms)
   BULLET::::- In first degree beta burns the damage is largely limited to epidermis. Dry or wet desquamation occurs; dry scabs are formed, then heal rapidly, leaving a depigmented area surrounded with irregular area of increased pigmentation. The skin pigmentation returns to normal within several weeks.
  
  BULLET::::- Second degree beta burns lead to formation of blisters.
   BULLET::::- "Snow blindness", a burning of the cornea, is caused by the intense ultraviolet solar radiation multiplied by sunlit snow. Snow blindness may be prevented by wearing dark sunglasses or goggles.
  
  BULLET::::- "Burns" can occur when dealing with camp stoves. Boiling pots are overturned, clogged fuel lines explode, hot metal is touched with bare skin. Burns are also caused by campfires, cookfires and bonfires.
  
  BULLET::::- "Lacerations" may be caused by careless use of knives or axes, or contact with sharp rocks or barbed wire. Tetanus and other infections can result.
   BULLET::::- Pernio or chilblains are inflammation of the skin from exposure to wet, cold (non-freezing) conditions. They can appear as various types of ulcers and blisters.
  
  BULLET::::- Bullous pemphigoid is a condition that causes itchy blisters over the body that can mimic frostbite. It does not require exposure to cold to develop.
  
  BULLET::::- Levamisole toxicity is a vasculitis that can appear similar to frostbite. It is caused by contamination of cocaine by levamisole. Skin lesions can look similar those of frostbite, but do not require cold exposure to occur.
   Section::::Epidemiology.
  
  In the United States, over two million people required medical attention for thermal burns every year. About 1 in 30 of those victims (75,000) are hospitalized for thermal burns every year, with a third of those patients staying in the hospital for more than two months. About 14,000 Americans die each year from burns.
  
  Section::::Epidemiology.:Children.
   In those hospitalized from scalds or fire burns, 310% are from assault. Reasons include: child abuse, personal disputes, spousal abuse, elder abuse, and business disputes. An immersion injury or immersion scald may indicate child abuse. It is created when an extremity, or sometimes the buttocks are held under the surface of hot water. It typically produces a sharp upper border and is often symmetrical, known as "sock burns", "glove burns", or "zebra stripes" - where folds have prevented certain areas from burning. Deliberate cigarette burns are preferentially found on the face, or the back of the hands and feet. Other high-risk signs of potential abuse include: circumferential burns, the absence of splash marks, a burn of uniform depth, and association with other signs of neglect or abuse.
   BULLET::::- Early on, the primary symptom is loss of feeling in the skin. In the affected areas, the skin is numb, and possibly swollen, with a reddened border.
  
  BULLET::::- In the weeks after injury, the skin's surface may slough off.
  
  Section::::Signs and symptoms.:Second degree.
  
  BULLET::::- In second degree frostbite, the skin develops clear blisters early on, and the skin's surface hardens.
  
  BULLET::::- In the weeks after injury, this hardened, blistered skin dries, blackens, and peels.
  
  BULLET::::- At this stage, lasting cold sensitivity and numbness can develop.
  
  Section::::Signs and symptoms.:Third degree.
   Thick skin is more prone to superficial burns because of the simple fact that there's more to burn before it gets deep. Skin thickness varies throughout the body, from 0.5mm of the eye lids to 6mm in the soles of the feet. Skin thickness overall varies with age, being thinner at extremes of age.
  
  External factors on the skin like hair, moisture or oils can also help ease and delay the burn. Another factor is skin circulation, which is used to dissipate heat imprinted on the skin.
  
  Section::::Causes.
  
  Section::::Causes.:Hot liquids and steam.
   BULLET::::- "Heat exhaustion", possibly developing into "heatstroke", can occur in hot weather, particularly if one is dehydrated or dressed too warmly. The risk of heatstroke can be minimized by avoiding direct sun, and staying wet when possible. This is a life-threatening condition: a victim must be cooled off and transported to a hospital immediately.
   Scalding is a type of thermal burn caused by boiling water and steam, commonly suffered by children. Scalds are commonly caused by accidental spilling of hot liquids, having water temperature too high for baths and showers, steam from boiling water or heated food, or getting splattered by hot cooking oil. Scalding is usually a first- or second-degree burn, and third-degree burn can sometimes result from prolonged contact. Nearly three quarters of all burn injuries suffered by young children is scalding.
  
  Section::::Causes.:Fire.
   Severe burn patients are often treated through trauma resuscitation, airway management, fluid resuscitation, blood transfusion, wound management, and skin grafting, as well as the use of antibiotics.
  
  Section::::Outcome.
  