How does skin freeze to ice?
108664
skin is primarily water so it stands to reason if too cold it will freeze as water does
609524
You can make your own ice pack by combining one part rubbing alcohol and two parts water, then filling a plastic bag with this (two, preferably) and freezing it. The alcohol keeps the pack from freezing completely, so you can mold it to any part of your body.
431655
the body thinks the brain is freezing, so it sends blood up there really fast to heat it up. too much cold, too much blood in head, headache. next time it happens, take an ice cube and put it on your neck. the blood will flow there instead, and you won't have a headache.
474500
Dry ice is frozen carbon dioxide.  The temperature at the surface (where it is sublimating back into gas) is -79 degrees Celsius (about -109 degrees Fahrenheit).\n\nSo yeah, it's really really cold, and if you touch it for too long the tissue damage it creates feels almost exactly like a burn.
640820
No. For humans, this concept is almost impossible. There is nothing in our body that could help us sustain life, when our body's are frozen.\n\nAlso, when frozen, ice crystals develop. As small as they are, all of them do extensive damage to muscles and tissues. This means if you were to be defrosted, you wouldn't nearly be the same. Even without ice crystals, freezing and unfreezing tissue causes damage.\n\nBlood also ices. Nothing can be done to repair that.
1042591
Assumption is that you have a source of food that you can freeze.\n\nFreezing is a tough science, because of the water content in the food.  Water expands when the temperature drip to below 4 degree C.\n\nImplication, Within the Food, the cell that has water in them(Most does) the water expands, and damage the cell walls.  Thus when you eat the food, the food, is mushy, not firm.\n\nRead the History of Birdeyes Fish Finger, to learn how they solve the issue.
726926
Salt... When applied to ice, the salt (NaCl) dissolves into the water creating a salt water mixture which has a lower freezing point than pure water.\n\n10% salt solution freezes at 20 F (-6 C)\n20% salt solution freezes at 2 F (-16 C)\n\nSalt becomes less effective at temperatures below 0F (-32 C).\n\nEnjoy!
819865
Conservation of energy.\n\nCalculate the amount of heat stored in the 28ºC water using 0ºC as the starting point.  This energy must first melt the ice, for which you'll need to use the heat of fusion of water.  The remainder of the energy will warm up the entire amount of water.
260241
Ice (cryotherapy).  If you do not have an 'icepack' designed for this, you can use a large bag of frozen vegetables (peas or corn).\n\nPlace the 'icepack' or frozen veggie bag in a thin pillowcase cover and then apply it to your shoulder for about 20 minutes.  Follow this with 1 hour without ice to allow healing blood flow and to prevent frostbite.  Repeat as needed.\n\nInitially, it should feel very cold, then ache, then burn, then numb.  Do not exceed 20 minutes of use at a time - do not want to turn you into 'freezer burn'!\n\nGood luck.
499459
A very good question.\n\nAlmost all common chemical will contract upon freezing, but not water. \nThe special hydrogen bonding that forces the water molecule to be very close to eacher other in liquid phase.\n\nThe molecule of HOH is not straight, but in a V shape. About 105 degree.\nIn liquid phase the V shape can over lap each other. Go look up the water structure at\nhttp://www.chem1.com/acad/sci/aboutwater.html\n\nDuring freezing, the water molecule are force to line up, and the V shape molecule are line up side by side and no longer over lap.  This takes more room. So it expands.\n\nGo look up the ice molecule structure at http://www.uwgb.edu/dutchs/PETROLGY/Ice%20Structure.HTM\n\nIts not easy to see the true structure, but these will at least gives you a picture.\n\nKeep asking questions, enjoy.
353707
take ibuprofen and put ice on it
926505
Dry ice is about -110 degrees, so no, you definitely shouldn't touch it with bare skin. It can cause tissue damage.\n\nI did see something about medical/dermatological uses of dry ice, but like lasers, chemicals, etc that a doctor might use on you this would be a special technique only suited to a trained professional. You definitely shouldn't be slapping dry ice on your face at home with the idea that it's going to be some sort of beauty treatment!
613595
It breaks the hydrogen bonds between water molecules to aid in the melting process. Since this energy is used to break bonds, it can't heat the ice.
785888
It all depends on the exact composition of air. Air is a mixture of gasses, Nitrogen, Oxygen, Carbon Dioxide, Carbon monoxide and small amounts of various other gasses. Freezing occurs when the gaseous mixture turns from a liquid and then into a solid. Although it may theoretically be possible to solidify Air, it has not actually been reached.
60893
Sodium Chloride (NaCl), or salt, lowers the freezing point of water.  Putting salt on ice turns it back into water UNTIL the temps drop below the point where the salt water will freeze again which is between -9°C (15°F) and -21°C (-6°F) depending on the amount of salt suspened in the water.
86483
Actually, Gonpatrick, the original question is quite correct: Unlike most substances, water does actually expand when it is cooled, over a narrow temperature range from about 4 degrees C to 0 degrees C (the freezing point.)  This is why water freezes from the top down: the cooler water that is closer to freezing is less dense than, and so floats above, slightly warmer water.  (Above 4 degrees C, water expands when it is heated just like most other substances.) When the water freezes it expands some more, which is why ice floats.\n\nThe reason why it does this has to do with the way water molecules are put together.  The two hydrogens and one oxygen in H2O are assembled in a triangular pattern, with one part of the molecule more positive and the other more negative.  Above 4 degrees C, the molecules move freely around each other, but when it gets close to its freezing temp, the molecules start to align themselves with the positive part of one molecule near the negative part of another, ultimately forming, when it freezes, a hexagonal pattern.  This arrangement takes up more room than when the molecules are free to move around.
1058355
its actually a general question. depending on the conditions and by what. even though blood is a bit thicker than water. the body is 70 percent water. water can freeze at 32 degree's and at 0 degree's can freeze solid in 45 minutes. the body itself will always freeze slower say if your in the artic naked with a glass of water. because the skin acts as a thermal barrier, it would take longer. put a cup of blood and a cup of water in the freezer and the blood will gel up at 0 degrees or less. the water in blood will freeze, but not the plasma. there is what is called freeze dried blood that can be used in research. if you put blood and water in hydrogen, they both would freeze solid as its 220 below zero.