Is it true that you will never get the EXACT same cold twice?
958040
That's true.  The cold virus mutates constantly.  If you were exposed to the exact same virus again, your body "remembers" and can fight it off before you have any cold symptoms.  However, a new mutation is not recognized, and can produce all the symptoms all over again.\n\nRe: the flu shot.  (above) \nInfluenza is NOT the cold virus - it's completely different, and mutates much more slowly.  That's why they can predict with reasonable certainty which variety needs to be in the flu shot.  It is NOT worthless.
946687
Colds are actually contageous for at least a day or two before you show any symptoms.  Then once it hits, you remain contageous for another three to four days.
72303
The short answer is no. \n\nIn science, it is important that results be repeatable. This is especially true when dealing with some phenomenon like cold fusion which appears to violate all the principles that we understand. \n\nPons and Fleishman and others tried to reproduce the observations, and were unable to do so reliably. A recent review by the Department of Energy of 15 years of research and efforts in the field reached the conclusion that this phenomenon does not exist, or at least cannot be verified.
761155
Yes, sometimes, especially if you are sick already!
620909
Absolutely not!  \n\nIf people who have allergies and sneeze numerous times in a row (my friend can sneeze more than 10 times in a row during allergy season) suffered a stopped heart, they'd die by the time the sneezing fit was over.
812070
it just means your body is different from everyone else, like it should be... if you feel you need to, go ask your doctor... I also am a very cold person, and i am just fine!
1006415
'Wrap up' advice to stop colds\nScientists say cold noses reduce ability to fight virus attacks\n\nMonday, November 14, 2005; Posted: 4:47 p.m. EST (21:47 GMT) \n\nLONDON, England (CNN) -- British researchers into the common cold say "catching a chill" really does help colds develop -- and are advising to "wrap up warm" to keep viruses at bay.\n\nMothers and grandmothers have long warned that chilling the surface of the body, through wet clothes, feet and hair, causes common cold symptoms to develop. \n\nBut much previous research has dismissed any link between chilling and viral infection as having no scientific basis. \n\nNow researchers in Cardiff, Wales, say they can prove drops in temperature to the body really can cause a cold to develop. (Watch what they did to 'chill' people in the study -- 3:24)\n\nClaire Johnson and Professor Ron Eccles, from Cardiff University's Common Cold Center, recruited 180 volunteers, half of whom they got to immerse their feet in ice and cold water for 20 minutes.\n\nThe other 90 in tests during the common cold "season" sat with their feet in an empty bowl. \n\nDuring the next four or five days, almost a third (29 percent) of the chilled volunteers developed cold symptoms -- compared to just 9 percent in the control group, the scientists said. \n\nProfessor Eccles said there was a simple explanation as to why chilly feet could lead to the development of cold virus symptoms. \n\n"When colds are circulating in the community many people are mildly infected but show no symptoms," he said, according to the UK's Press Association. \n\n"If they become chilled this causes a pronounced constriction of the blood vessels in the nose and shuts off the warm blood that supplies the white cells that fight infection. \n\n"The reduced defences in the nose allow the virus to get stronger and common cold symptoms develop. \n\n"Although the chilled subject believes they have `caught a cold' what has in fact happened is that the dormant infection has taken hold." \n\nThe researchers, writing in the UK medical journal Family Practice, said that common colds were more prevalent in the winter than the summer, and this could be related to an increased incidence of chilling causing more clinical colds. \n\nBut they also suggested that another explanation could be that our noses are colder in the winter. \n\nProfessor Eccles added: "A cold nose may be one of the major factors that causes common colds to be seasonal. \n\n"When the cold weather comes we wrap ourselves up in winter coats to keep warm but our nose is directly exposed to the cold air. \n\n"Cooling of the nose slows down clearance of viruses from the nose and slows down the white cells that fight infection. \n\n"Mothers can now be confident in their advice to children to wrap up well in winter." \n\nCardiff's Common Cold Center says it is the world's only center dedicated to researching and testing new medicines for the treatment of flu and the common cold.
1046410
once in two days in winter and everyday in others
172157
Not usually.\nOnce we have recovered from a bacterial or viral infection our body's defense system can very quickly protect us against a second attack - this is 'natural immunity'.\nWe make use of this mechanism in immunisation by injecting (usually) weakened or inactive microbes (or part of a microbe) which creates an immune response - production of antibodies. We are immune to future attacks.\n\nA second dose of a disease is unlikely but possible - I have had measles twice!\nScarlet fever is easily treated with antibiotics, though I've had this too. It is not pleasant.\n\nHave a look here:
983341
I am getting over a sinus cold. On Monday, I didn't keep count throughout the day but in addition to the normal sneezing, I had 3 different sneezing fits where I sneezed at least 15 times each. It was awful. It was like sneeze, 7 seconds, sneeze, 7 seconds, sneeze. \n\nSo I'd guess maybe close to 50 times total.
168989
Sure. It's not uncommon. The percentages change but the last one I recall was that about 1 in 3 people have it again within 6 months. Forgive me if my recall is not entirely correct but the answer is definitely yes.
1140518
Nonsensical question - nobody can answer this.  And nobody ever says "twice as cold" simply because they know it is meaningless.\n\nThermo, your calculations (below) are WRONG.
831194
No.  The flu shot has nothing to do with cold viruses.  You've just been lucky to not have gotten a cold.  But it wasn't because of the flu shot you got 3 years ago.
1145466
not if you have a cold. i have a cold and it's awful...........plus when your conjested don't excersise........you need to breathe right
820475
The common cold is transmitted from person to person, it is not caused by being cold.  Although there is some research that suggests that being cold leaves you more open to catching a cold.  There are two main theories:\n\n1) Although not entirely understood, the theory is that when you get cold your blood concentrates around your vital organs in order to keep them warm.  This means that your extremities become very cold, in particular your nose.  The theory goes that your nose acts like a first line of defense and can reduce the chances of the virus making its way to your respiratory tract.  When your cold the blood supply to the nose is reduced and this first line of defense is lost.\n\n2) Being cold weakens your immune system so you are more likely to develop the symptoms of a cold.
465986
I know someone who had it 3 times--and each time was pretty bad.  He is a very rare case though!  If you even THINK you may have it, stay away from people like infants and the elderly--you may be contagious and you do not want to give it to someone who has a compromised immune system!
1117871
Yes.\nSince a typical small snow crystal might contain 1018 water molecules, we see that about 1015 of these molecules will be different from the rest.  These unusual molecules will be randomly scattered throughout the snow crystal, giving it a unique design.  The probability that two snow crystals would have exactly the same layout of these molecules is very, very, very small.  Even with 1024 crystals per year, the odds of it happening within the lifetime of the Universe is indistinguishable from zero.