With summer on the horizon, we know it’s time to slather on the sunscreen and reapply, but how much do we really know about this magical lotion that’s said to protect against sunburn and prevent skin cancer? For all the mysteries that still remain about the sun and how it affects us, we can rest assured knowing that we have these 10 facts about sunscreen covered:

1. There is No Evidence that the Chemicals in Sunscreen are Not Safe: Despite ongoing controversy over the safety of the chemicals in sunscreens, most scientists and doctors agree that there is no evidence that sunscreen ingredients are harmful to humans. The argument that sunscreen ingredients are carcinogenic, block vitamin D or alter the body’s hormone system will require further research and experimental studies before any conclusions are drawn.
2. The Higher the SPF Number, the Smaller the Difference: It’s a common misconception that a higher SPF number means you are doubly or triply protected. A higher number does indicate more protection, but it doesn’t give you two to three times as much protection as one with an SPF 15. Sunscreens with SPF 15 filter out roughly 93 percent of UVB rays and SPF 30 sunscreens filter about 97 percent. The protection slightly increases as the SPF number gets higher, but only by one percent (98) for SPF 50 and two percent (99) for SPF 100 sunscreens. The fact is no one sunscreen will protect you completely.
3. SPF Numbers Only Refer to UVB Ray Protection: The sun protection factor (SPF) number on sunscreens only measures protection against UVB rays, the skin-burning rays. There is no current FDA-approved rating system for measuring protection from UVA rays, which cause aging of the skin. To ensure coverage against UVB and UVA rays, you should use a "broad-spectrum" sunscreen, or one that contains avobenzone (Parsol 1789), ecamsule, zinc oxide or titanium dioxide.
4. There’s a Difference Between Waterproof and Water-Resistant Sunscreen: Sunscreens that are labeled "waterproof" or "water-resistant" are slightly different in their chemical makeup and water tolerance. Water-resistant sunscreens can maintain their SPF level after 40 minutes of water exposure, and waterproof sunscreens can maintain their SPF level after 80 minutes of water exposure, according to the FDA. If you’re plan on being in the water or participating in outdoor activities, you should choose a water-resistant or waterproof sunscreen for optimal protection.
5. Sunscreen Does Not Cause Vitamin D Deficiency: For years, people have blamed sunscreen and dermatologists’ pleas to stay out of the sun as the leading cause for vitamin D deficiency in Americans. However, we now know that there is little to no evidence that shows sunscreens cause vitamin D deficiency, and people can get the recommended amount of vitamin D from other sources than just the sun, such as taking dietary supplements and eating foods like salmon, milk and eggs.
6. Sunscreen is Not Fail-Safe: We now know that sunscreen is not fail-safe because it is not a guaranteed protection against all of the sun’s harmful rays. There is also no supporting evidence that sunscreens protect you from developing malignant melanoma, the deadliest kind of skin cancer. Sunscreen alone will not fully protect you from the sun or from developing skin cancer. In addition to wearing sunscreen, you should also seek shade, wear protective clothing, avoid peak hours of sun exposure and monitor the UV index.
7. One Ounce of Sunscreen is Needed to Cover Your Body: We now know that one ounce, equivalent to a full shot glass, is the recommended amount of sunscreen needed to cover your exposed skin. You should apply sunscreen liberally and reapply every two hours, especially after perspiring, swimming or towel-drying. Sunscreen is something you definitely don’t have to go easy on. Don’t forget to protect the often-missed parts of the body, like the lips, ears, hands, feet, neck and scalp.
8. Everyone Should Use Sunscreen, Regardless of Skin Color: People of all races and ethnicities are at risk for developing skin cancer, and should wear sunscreen to protect themselves from UV radiation. We know that people with fair skin and a large number of freckles and moles have a greater chance of burning and developing skin cancer, but people with darker skin can also burn and develop skin cancer as well. Dark-skinned individuals are also more likely to be diagnosed with skin cancer in the later stages when it is more dangerous and could be fatal.
9. Sunscreen is Needed in All Types of Weather: Whether it’s sunny, cloudy or snowing outside, you still need sunscreen to stay protected all year long. Ultraviolet rays can do a significant amount of damage even when the sun is not at its hottest. According to the Skin Cancer Foundation, people experience some of the severest sunburns because they did not protect themselves on cloudy days, where up to 40 percent of the sun’s radiation can get through. So, whether you’re hitting the slopes or riding the waves, you need to wear sunscreen in every season and every type of weather.
10. Sunscreens Have a Maximum Shelf Life of Three Years: According to the FDA, all sunscreens have to be stable at their original strength for at least three years, unless otherwise indicated by an expiration date. Sunscreens lose their effectiveness after three years, especially when the bottle is exposed to direct sunlight, extreme changes in temperature or left open. Sunscreen is said to have a shelf life of three years. However, if you’re using the appropriate amount of sunscreen daily, you shouldn’t have bottles of sunscreen sitting around for more than one year!

As medical technology continues to develop at a strident pace, transplant procedures also continue to push the boundaries of what anyone thought was ever possible. Still, even before we reached the technological triumphs of today, there are plenty of accounts of very remarkable transplants. Sometimes there were great risks; sometimes they paid off, and sometimes they didn’t. It can be somewhat difficult to define a successful transplant. Ideally, the organs transplanted should function as long as the person receiving them lives, but this is not always the case. Even with a "successful" transplant procedure, a body’s immune system can reject the new organ. Despite these obstacles, there have still been monumental achievements in transplant procedures that are worth noting and still plenty more anticipated triumphs in the future.

1. First Human Heart Transplant: Though this procedure has become more commonplace since its original occurrence in 1967, the first successful heart transplant has to be among the most impressive transplants ever; heart transplant procedures are still considered very complex procedures and take great amounts of skill to pull off. Having experimented for several years with animal heart transplants (mostly dogs), Dr. Christiaan Barnard became the first to successfully transplant a human heart. The operation lasted nine hours and used a team of thirty people. The patient undergoing the operation, Louis Washkansky, suffered from diabetes and incurable heart disease, making the first ever heart transplant an ethical procedure. Washkansky survived the operation with a working, beating heart, but unfortunately died eighteen days later from pneumonia as he was taking immunosuppressive drugs.
2. First Ovary Transplant: One of the most recent achievements in transplant surgery, in 2008 one woman was the first ever to receive a whole ovary transplant to result in a successful pregnancy. Experiencing an early menopause at age 15 when her ovaries stopped producing hormones, she received a donor ovary from her identical twin sister. While this operation rests on the condition that the donor ovary being genetically identical to the receptor, it opens the possibility of removing and freezing an ovary prior to cancer treatment. The operation involved microsurgery, connecting blood vessels as small as half a millimeter in diameter. Three months after the surgery, the patient was ovulating normally again.
3. First and Only Penis Transplant: The first ever penis transplant is a kind of funny case, not just because it has the word penis in it. After "an unfortunate traumatic accident" in 2005 that left an understandably anonymous man with a small stump for a penis, unable to urinate or have sex normally, he and his wife felt a strong need for a penis transplant procedure. After a 15-hour microsurgery, Dr. Hu Weilie at Gaungzhou General Hospital in China managed to successful attach the donor penis. Unfortunately, we will never know if the first transplanted penis had the ability to perform sex adequately, as the penis was removed only two weeks later due to "a severe psychological problem of the recipient and his wife."
4. First Corneal Transplant: The first corneal transplant was also the first successful human tissue transplant. In 1905, Dr. Eduard Zirm of Czechoslovakia was tending to blind patient Alois Glogar around the same time a young boy was brought into the clinic due to an accident that left metal pieces in his eyes. Unable to save the boys eyes, Zirm enucleated them and saved the corneas for transplantation into Glogar’s. Despite having the necessary microscopic technology to suture the cornea, one of Golgar’s eyes regained vision after the surgery and he was able to return to work. While eye surgeons around the world had been unsuccessful in this operation for hundreds of years, Zirm’s success has been credited with advances in anesthesia and asepsis.
5. First Gland Xenotransplantation (Interspecies Transplant): That have been documented instances of xenotransplantation since the 1600s. Most records show that they were largely unsuccessful, and today, the idea of xenotransplantation is still considered controversial in part due to the very low success rate. However, there is one peculiar case in the 1920s that appears to have had moderate success. Dr. Serge Voronoff had been experimenting with glandular transplantation for a few years. In 1920, he extracted thin slices (a few millimeters wide) of testicles from chimpanzees and baboons and implanted them inside a human patient’s scrotum; the thinness of the tissue samples allowed the foreign tissue to fuse with the human tissue eventually. The transplantation allegedly resulted in the "rejuvenation" of old men. Unfortunately, most of these experiments were disproven after scientific discoveries began to show this simply wasn’t possible. The rejuvenation that Voronoff’s patients experienced was merely a placebo effect. Regardless, this was quite an impressive undertaking for xenotransplantation at the time.
6. First Organ Xenotransplantation (Interspecies Transplant): There are very few published cases of successful xenotransplantation. The longest a human has survived with a vital organ of another animal is at most a couple months. However, there has been a successful case of a pig’s liver being transplanted to a woman as a "bridge" to hold them over until human transplants were available. The liver was kept outside the body in a plastic bag and hooked up to her main liver arteries. Fortunately, she survived long enough to receive a human liver. It is difficult to determine how necessary the transplantation was; however, as genetic technology continues to alter the organs of animals similar to us, xenotransplantation will become a more common, necessary procedure. There simply is not a large enough supply of human organs to fill the current demand.
7. First Full Face Transplant: Perhaps the most recent achievement in the transplantation field, in the summer of 2010, a Spanish man named Oscar became the first to receive a full face transplant. After a horrid shooting accident, his entire facial skin and muscles — including his noes and lips — needed replacement. A team of 30 experts helped in the 24-hour long operation at the hospital in Barcelona. Led by Dr. J.P. Barret, they transplanted muscles, lips, maxilla, palate, all teeth, cheekbones, and the mandible through a combination of plastic surgery and micro-neurovascular surgery techniques. Doctors expect his to regain up to 90% of his facial functions. Though he had already had 10 partial operations prior to the surgery, this was the first full face transplant performed successfully.
8. Living Donor Liver Transplant: Living donor liver transplantation (LDLT) is remarkable for two reasons: (1) Liver transplantation is an expensive and complex surgery involving three surgeons, one anesthesiologist, and a team of supporting nurses; (2) the remarkable regenerative capacities of the human liver allows a liver to regenerate even after 55 to 70% of it is removed. The first record of successful LDLT was in 1989 when two-year-old Alyssa Smith received a portion of her mother’s liver. Since then it has become a more common, acceptable procedure given the high demand for human organs. Although living donors must accept the risk of death prior to surgery, the mortality rate of living donors in the United States is low. Any member of the family or even a volunteer can donate their liver.
9. First Lung Transplant: Interestingly, the first successful lung transplant was a combination of a lung and heart transplant. Dr. Bruce Reitz led the surgery on Mary Gohlke in 1981 at Stanford Hospital. The transplant team at Stanford is the longest continually active team performing these procedures. During the operation, the patient is connected to a heart-lung machine, which circulates and oxygenates blood. As the donor organs warm up to body temperature, the lungs begin to inflate. Sometimes the heart fibrillates at first due to cardiac muscles not contracting synchronously. However, internal paddles can apply a small electric shock to the heart to restore proper rhythm.
10. First Hand Transplant: There is something very elegant and comforting in the idea of a hand transplant. Hands are characteristics that set us apart from most other species, so the ability to reshape any deformity that may occur in them seems nothing short of amazing. The first hand transplant ever recorded was in Ecuador in 1964; however, the patient suffered from transplant rejection (a common problem to transplants in such an early time period). The first short-term success occurred in France in 1998. While the operation was successful, the patient had trouble with the idea of his transplanted hand and failed to follow the prescribed post-operative drug and physiotherapy; the hand was removed at his request a couple years later. Finally, in 1999, the first hand transplant to achieve prolonged success happened in Louisville, Kentucky. Hand transplants have become more common and successful, but there is still a lot to refine in the procedure so that it can achieve longer success and a lower cost of surgery and rehabilitation.

We have all felt the sting of a poor night’s sleep. With endlessly busy lives full of forty hour work weeks, carpools, dentist appointments, school, family, friends, and so much more, it is nearly impossible to avoid late nights and early mornings. But there is no doubt that prolonged sleeplessness can have some very serious and very negative effects on our bodies and our minds. More and more often, individuals with chronic sleeplessness are turning to prescription sleep medications for aid. Prescription sleeping pills have increased in sale by over 60 percent in the last decade according to a 2006 New York Times article. With pharmacists filling more prescriptions for sleep aid and more and more individuals complaining of sleeplessness, concerns about the health risks of both sleeping pills and sleeplessness have elevated drastically. The following lists the 10 most severe and dangerous side effects sleeplessness can have:

1. Death: While sleeplessness has not been proven to actually cause death, there are several factors involved with insomnia and poor sleeping habits that may. Those who suffer from sleeplessness are significantly more likely to turn to alcohol abuse and substance abuse. Moreover, individuals who regularly get little to no sleep are far more likely to suffer from anxiety and depression. With the combination of alcohol and controlled substances and depression, insomnia can have some very dire consequences. Generally, experts believe that the body would merely shut down and sleep, before an individual would actually die from not sleeping. However, there has been very little research actually performed around this hypothesis because the experiment is just too dangerous.
2. Psychosis: One of the most troublesome side effects of severe sleep deprivation is psychosis. When an individual suffers from psychosis they are often described as having a complete break from reality. They may experience personality changes or hallucinations. When associated with sleep deprivation, psychosis is usually only temporary, but it can lead to some very serious issues. Accompanied by psychosis an individual may experience severe depression and anxiety as well. These conditions drastically impair an individual’s ability to perform everyday tasks and worsen an individual’s quality of life.
3. Obesity: It is no secret that obesity rates throughout America have escalated into a huge problem in recent years. Many health experts are calling the current obesity trend throughout the country an epidemic. Several studies preformed over that past decade have shown that individuals who sleep less are more likely to overeat and, therefore, more likely to become obese. Furthermore, stress and depression (two side effects of sleeplessness) have been shown to contribute to an individual’s weight gain. Obesity is a very dangerous condition. Experts have calculated that obesity is not only more expensive for both the country and an individual than smoking cigarettes, but is also more deadly than smoking cigarettes. While (of course) one night of not sleeping will not make you obese, a constant lifestyle of sleeping too little may.
4. Type 2 Diabetes: Numerous studies have shown that a person suffering from sleep deprivation is much more susceptible to developing Type 2 Diabetes than a person who gets an adequate amount of sleep each night. It is important to note, however, that this result is only associated with chronic insomnia, not just poor sleeping habits. Type 2 Diabetes is a very serious condition that affects millions of people worldwide. It is associated with several other debilitating conditions as well, including hypertension, high cholesterol, blindness, kidney failure, obesity, and many more.
5. Suppressed Immune System: Lack of sleep affects almost all aspects of our physiological and psychological health. Sleeplessness has a negative effect on our body’s ability to heal itself. In other words, insomnia and frequent sleepless nights may lead to a decrease in your immune system’s ability to function properly. A weakened immune system (as one might imagine) can lead to several very serious complications. For example, in the study linked to above, individuals who received less than seven hours of sleep a night were almost three times more likely to develop the common cold than those who received eight or more hours of sleep. Even more worrisome, a weakened immune system can lead to chronic disease and severe infections. Several studies have put forth data that suggests a link between the production of disease-fighting cells (white blood cells) and adequate sleep.
6. Memory Loss: Another serious side effect insomnia can have is memory loss. It is widely known that sleep is the time during which our brains process all the information that we have gathered during the day. It is during the REM (Rapid Eye Movement) stage of sleep that our brain processes this information and stores it as memory. Individuals who do not get an adequate amount of sleep at night will not enter the REM stages of sleep as often and, therefore, will not be capable of storing as many memories. Memory loss can affect several different aspects of an individual’s life, including their personal relationships as well as their ability to think and learn. While it is known that sleep deprivation has negative cognitive consequences, the mechanisms by which sleep deprivation affects brain function remains fairly unknown to scientists.
7. Loss of Self Control: One of the more serious side effects of sleeplessness is the effects that it can have on natural hormone levels in the body. Scientists have observed that lack of sleep can suppress certain growth hormones that are naturally produced in the body. These growth hormones help promote a balanced reaction to stressors of the immune system, sex drive, and mood. This means that individuals suffering from sleeplessness may feel that they are losing self control. Researchers have observed low levels of melatonin in individuals suffering from insomnia, which regulates the sleep-wake cycle in humans by chemically causing drowsiness. Also, many studies have noticed a correlation between sleeplessness and elevated levels of the stress hormone cortisol.
8. Decreased Concentration: We can probably agree that trying to concentrate after getting a poor night’s sleep can be extremely difficult. Everyday endless numbers of people both young and old stumble out of bed and consume outrageous amounts of caffeine in order to stay awake and alert throughout the day. While decreased concentration is one of the tamer side effects of sleep deprivation, it can have some very dire consequences. Poor concentration due to lack of sleep can (and has) led to several automobile accidents. Every year, it is estimated that there are more than 50,000 adolescents who are involved in car accidents caused by lack of sleep. However, because sleep deprivation cannot be measured posthumously, it is impossible to determine whether it is a factor in accidents when the driver does not survive.
9. Pain: While it isn’t all that difficult to believe that chronic pain may cause someone to have trouble sleeping, many researchers believe that lack of sleep may actually cause pain. It is widely known that individuals who suffer from sleeplessness have an increased likelihood of also suffering from severe migraines. A well-known study within the field performed in 1869, indicated that adequate sleep protects individuals from migraine attacks. According to this study, 29 percent of the participants’ migraines were actually caused by insomnia. It is also widely believed (although the science behind it is a bit uncertain) that lack of sleep causes increased pain in trigger points in the muscles.
10. Dizziness and Nausea: As two of the more well known side effects of sleeplessness, dizziness and nausea are not the scariest consequences poor sleep can have, but they are the most common. These side effects are tangible even after only two consistent nights without much rest. While nausea and dizziness are not necessarily dangerous in themselves, they can lead to some very serious hazards throughout the day. An individual experiencing both nausea and dizziness will have more trouble focusing on the task they have at hand. Moreover, dizziness can severely impair an individual’s ability to operate a vehicle safely, making them a danger to both themselves and others.