Fire

Scientists in west florida university performed an experiment to see the effect of fire on a human corpse. Once on fire the outer skin goes first, crisping and crackling before it burns away pretty quickly. The dermal layers of the skin vanish too after about 5 minutes. By then the fire has burned away your shell and starts on the fat layer. Fat is an effective fuel as flammable material acts like a candle wick. The fat melts away, absorbs into the wick and then burns for hours. Flames also dry out muscles, contracting them and making the body move. The fire will burn itself out only when the bones remain, unless they break to expose the marrow. Teeth don’t burn either.

Cold

Normal body temperature is just over 37 degrees celcius. At 36c your reaction times and judgement become impaired. At 35c walking may be difficult and you will struggle to write your own name, and hypothermia sets in. At 33C you may become irrational, stripping off your clothing. At 32c most people will collapse. When the bodys temperature drops to about 30 degrees celcius, all bodily functions slow down and the person will likely lose consciousness.. Fatigue, clumsiness and a delay in reacting to outside stimuli are among the first symptoms.Cardiac arrhythmia sets in,. The heart will also gradually slow, along with lung function, until the rest of the body starves of oxygen. In addition, the renal system quickly fails, flooding the body with diluted versions of urine. This substance leaks into the blood and organs, causing shock or other heart problems. The body will experience frostbite, as the fingers feet and toes begin to freeze. If there is extreme wind blowing in your face, and you are forcing to keep your eyes open then your cornea may freeze.By 20c your heart will have stopped all together. The current record for lowest body temperature of a surviving human was 16c, a toddler was wandering out in -20c weather and her heart had stopped for 2 hours.

Starvation

The stomach physically shrinks, which can make it uncomfortable to start eating normal amounts again even if food arrives to save you. The heart and heart muscles also physically shrink; restricting the blood they can pump and drops the blood pressure. Prolonged starvation causes anaemia. In women #, menstruation can stop completely. When your body lacks enough sugars to burn, it starts breaking down fat along with glycogen reserves stored in muscle and liver cells. The body will then utilize the proteins within muscle tissue as a fuel source. When stored fat breaks down quickly it releases compounds called ketone bodies. They build up, leading to nausea and exhaustion. Your bones will permanently weaken after temporary starvation. The brain will also malfunction. Without the potassium and phosphorus in food, you may well physically lose grey matter in the brain- even if you resume eating. This results in permanent impaired brain function.

Radiation

The standard person is exposed to between 0.24 and 0.3 rem of radiation in a year. When a person is exposed to around 100 rems, the bloods lymphocyte cell count will be reduced, leaving the victim more susceptible to infection. This is often referred to as mild radiation sickness. Early symptoms of radiation sickness mimic those of flu and may be unnoticed unless a blood count is done. Symptoms inch headache,fever Diaroheaa and nausea/vomiting. According to data from Hiroshima and Nagasaki, show that symptoms may persist for up to 10 years, and may also have an increased long term risk for leukaemia and lymphoma. Radiation damage to the intestinal tract lining will cause nausea, blood vomiting and diarrhoea. The radiation will begin to destroy the cells in the body that divide rapidly. These include blood, reproductive and hair cells, and causes mutations to occur in dna and rna of surviving cells. Long term exposure will cause victims to become sterile. Radiation cause result in a greater higher chance of cancers, particularly thyroid cancer. The thyroid gland is susceptible to radioactive iodine. The iodine can destroy all or parts of the thyroid. At 200 rems the hair will start to fall out in clumps. Intense exposure to radioactive material at 1000 to 5000 rems would do immediate damage to small blood vessels and probably cause heart failure and death directly. Brain cells wont be affected unless exposure to 5000 rems of over, killing nerve cells and causing seizures and immediate death.

Pressure

Decompression sickness, commonly known as “the bends,” happens when the human body feels a sudden drop in surrounding pressure. Blood can no longer efficiently dissolve gases like nitrogen. Instead, the gases remain in the bloodstream as bubbles. In severe cases, the bubbles accumulate in blood vessels and block flow, resulting in dizziness, confusion, or even death. The mild form of decompression sickness usually results in joint pain and tissue swelling. Those who suffer from the severe version may experience conditions such as vertigo,paralysis and shock.

Water Drinking water to excess can cause severe harm to our body. Water intoxication causes all kinds of problems, the most deadly being hyponatrmia. This is because the levels of sodium in your blood is really low. This can lead to headache, fatigue, nausea, vomiting, frequent urination and mental disorientation. When a person drinks too much water in a short period of time, the kidneys cannot flush it out fast enough and the blood becomes waterlogged. Drawn to regions where the concentration of salt and other dissolved substances is higher, excess water leaves the blood and ultimately enters the cells, which swell to accommodate it. Most cells have room to stretch, but not in the case of neurons. Brain cells are tightly packed and there is almost 0 space to expand. This could lead to a swelling of an area of the brain, which can lead to seizures, coma, respiratory arrest, brain stem herniation and death. Another problem is that water contains pollutants. When you regularly drink more water than the safely recommended amounts, the pollutant can build to a level with which the body can no longer cope. Heat When exposed to extreme temperatures, the heart will beat faster as it increases the flow of blood to the skin, trying to keep critical internal organs from overheating. But if your core temperature continues to rise, sweat starts dripping then pouring from your glands so evaporation can cool your body. But if humidity leaves the sweat with no place to go and simply drops off the skin, your internal temperature will skyrocket. Our cardiovascular system has to work hard to get blood to the skins surface. For every one degree Celsius rise in core temperature, a typical person’s heartbeat goes up by 30 beats per minute. Heat exhaustion, the mildest form of heat related illness can cause cramps, fatigue, dizziness and nausea. If not treated the body could get heatstroke. When the body’s temperature rises above 103 degrees, cell damage can occur and organs begin to shut down. The intestines become more permeable, allowing harmful bacteria to get into the bloodstream. Heatstroke victim’s skin will become dark red due to increased blood flow. Eventually the person will lose consciousness as their organs will fail, and results in death. Corrosive Acids Chemical exposures to the skin can result in either temporary or permanent adverse health impacts. Chemicals that are swallowed and are in the bloodstream can be deadly. Some chemicals, e.g strong acids may leave permanent scars to the exposed areas.