Being outdoors means being exposed to the sun and ultraviolet (UV) radiation. Sun exposure in the heat can lead to heat exhaustion and UV rays can cause skin cancer, so it's important to avoid extreme temperatures and prolonged exposure to the sun's rays.
Always carry sunscreen and lip balm of adequate sun protection factor (SPF) and apply liberally, even in the wintertime. Wear sunglasses and/or a hat to protect your eyes. During the hot months, take breaks from the sun by finding a shady spot in which to cool down. Try to avoid the sun's peak UV exposure hours, usually between 10 a.m. and 2 p.m.
Another key aspect of outdoor safety (and directly related to sun safety considerations) is staying adequately hydrated. Most people underestimate their need for fluids, especially when engaging in high levels of outdoor activity, or and in the cold or heat, or at high altitude levels. Fluid requirements vary by body size, sex, and levels of activity, but one general guideline to follow is that your urine is light colored—just not clear. Dark colored urine is almost a sure sign that your kidneys are trying to conserve water and that you need more fluids in your body.
Extreme heat and cold are both serious realities outdoors. Weather is by nature unpredictable, so it is essential to be prepared for drastic shifts. Know what to do if you are in the vicinity of a thunderstorm (lightning), tornado, or wildfire.
Learn more about extreme heat and cold safety.
No matter how well you prepare, there is a good chance that if you spend time outdoors you'll encounter emergency medical situations. In these cases, there are a few things you should know to help mitigate any potential long-term negative health consequences.
The first rule of administering first aid in an emergency situation is to remain calm and rational, so that you can size up the scene and make an educated and decision on the next step to take. This includes making the scene safe for both victims and rescuers.
If you feel comfortable and it is safe to do so, approach and assess the victim. Ask him or her what's wrong and listen carefully. If you have something to write with, record what's wrong, as well as whatever treatment you administer. If you can safely do so, send someone to get help immediately as you begin to administer aid.
It is helpful to remember the fundamental emergency medical principle Primum non nocere, which is Latin for "First, do no harm." In other words, it may be better in some cases to do nothing at all rather than to risk worsening the situation. If you're not sure what to do, don't feel that you have to do something—instead, seek assistance. Never move an unconscious or seriously injured victim unless he or she is in danger from the environment, or needs to be moved to be treated or to be protected. Know the proper way to move victims. It is safest to always assume the worst and to be conservative in your treatments, unless the situation calls for more aggressive measures.