We all know the dangers of UV rays, and at most festivals, you're very exposed to them. You don't want a sunburn now, and you certainly don't want skin cancer later, so lather up. For festivals, I like to use sport spray-on sunblock; I can put it on myself without having to ask for help with the hard-to-reach areas, and it won't sweat off in the summer heat. Remember to reapply every few hours!
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2. HeadlampI refused to buy one of these for way too long because of the dork factor, but now I don't leave home without it. These convenient flashlights strap around your head on an elastic band (no more holding a mini-mag between your teeth). They're invaluable for nighttime Porta-John trips (the scariest thing ever) and they work well for mixing drinks, making beds, and all sorts of other things.
3. Toilet Paper
No one ever wants to talk about this, but every seasoned festivarian knows to bring a couple of rolls of Charmin from home. Porta-Johns often run out of toilet paper pretty quickly and even when they have paper, it's usually of the super-thin super-scratchy variety.
4. Baby Wipes
Not just for babies any more, wet wipes can keep you feeling fresh as a daisy even after a few days with no shower. Your hair will still be a rat's nest, but at least you won't smell. Remember what their original purpose is, as well... they can definitely be used for those treacherous Porta-John trips.
Festivals are required by law to have first aid services available and an ambulance on call, so if something major happens, there will be people to take care of you. However, they often don't dispense headache medicine, and sometimes it's more hassle than it's worth to get a simple band-aid put on, so make yourself a simple first-aid kit and save yourself some trouble.
You can't go to a music festival without your camera! Some festivals have rules about what types of camera you can bring (no movie cameras, etc.), but every outdoor festival that I know of lets you take snapshots. If you're worried about your expensive digital camera and you're not a hotshot photographer anyway, bring a few disposable cameras and you'll be set. Buy the super-cheap flashless cameras for daytime, and get the still-pretty-cheap flash cameras for evening snapshots of friends. Remember, it's generally in poor taste (and sometimes against the rules) to snap flash photos while a band is on stage.
7. Bottled Water and Sports Drinks
If festivals let you bring your own drinking water, do it, as water tends to be overpriced inside the gates. Remember, also, that if you're sweating heavily, it's important to keep the minerals (salt, calcium, potassium, etc.) in your body replenished as well, so electrolyte-rich sports drinks are a good choice, too. Heat exhaustion is serious business, so be prepared. If the festival doesn't allow outside beverages, you can usually bring your own reusable water bottle (a good choice by any measure) and fill up at a tap somewhere inside.
Some festivals don't allow coolers, but many do. I personally like the little foam coolers that you can throw over your shoulder and hold a couple of beers, but if you're just attending a festival for a day, or if you have more than yourself to feed, get yourself one of the nice new coolers a long handle and wheels. They can easily hold food and drinks for four people, and they double as a bench.
Between my little cooler and my little backpack, I can carry just about everything I need for the day. Carrying a purse (as much as I love them) just isn't practical at a festival; it's tough on your back and purses generally don't hold as much as you need. Keep the stuff you're carrying to a minimum and a backpack should provide you with more than enough space.
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