These are some tips that I live by and unfortunately found out the hard way most of the time.
Your pack you must have an extra pair of socks, warm clothes to layer up, hat and gloves, rain gear, food, your emergency kit, 2 water bottles, and your whistle. The water and the rain gear doesn't have to be inside your pack, but everything else needs to be inside to keep it dry. The emergency kit should be wrapped so if everything gets wet this will stay dry. For the summer it should have socks, gloves, hat, long underwear, some kind of freeze dried food or non-perishable food. You should also bring a map, compass, sharp knife, flashlight, batteries, tarp, some sort of fire-starter with matches or lighter.
If you plan on going out in the winter you should bring some extra clothing, hats, mittens, and a parka. Maybe throw in some gaitors as well. You might want to think about bringing snowshoes and ski poles depending on the weather. Just make sure you bring enough warm clothing and extras of everything because in winter things tend to get wet fast. If you can fit a sleeping bag and a pot to heat water in your group someone should bring one just in case someone gets wet and they don't get hypothermia.
If your with a group be sure you know who your with. If you have a beginner obviously your not going to go to the farthest route. If you you do have someone that is slower go at there pace or even have them lead. Don't try to push especially if your only on your way in remember you still have to get out. Don't make poor decisions because it may cause you to get lost or even injured. Always make sure everyone is staying together when there are different junctions, don't let someone fall behind and not know where to go. Keep a good pace so everyone can keep their strength and not wear out quickly. Also remember to have shorter breaks to keep your muscles warmed up.
Be considerate of the land and of those around you. In hiking the people coming back or going down have the right of way, so let them pass and then keep moving.
If you come to a stream try to find rocks or a log to cross, but beware of rotten logs. If its colder outside then there may be some ice buildup also. Way your options and find out what is the best. You may have to walk through the water to get across. If this happens don't cross the water if it's higher than your waist because the current could take you under. Use a stick or a ski pole if you brought one to help you maneuver across the river. You can also hold each others hands to help each other get across. This way if someone falls they have help to get back up to safety. If you want to keep your boots dry you may want to go across in your socks and put your boots back on the other side. Don't go across barefoot you may get injured and need medical attention. If you need to just keep your boots on and cross then take off your socks and dump out the water in your boots when you get across and put back on your dry socks and your on your way.
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