#1 PLAN AHEAD
Be sure to choose a trail that you know you can handle and have a trail map with you. There is not always cellular service in nature. Also be sure to choose a trail rating based on your ability. Some trails are marked "Difficult" for a reason. Don’t forget to check the weather before you head out!
Be sure to pack plenty of water. Hours in the hot sun and working out all those muscles can dehydrate you so be sure to pack plenty of water!
#3 PROPER CLOTHING
Layers are key when you are dressing for a hike. Summertime can be warm so you will want to have shorts and a comfortable tee shirt as a base layer. All your clothing should be quick-drying or wicking fabrics. You will sweat and may even get wet from the environment to its important that you are able to dry quickly - hiking while wet is not fun (or healthy)
#4 WEAR THE RIGHT FOOTWEAR
Summer weather may lead you to think "flip flops" or running shoes and no show socks. Your feet will meet rough terrain and need the support of a good pair of hiking boots and quality merino wool socks. Merino wool socks are breathable, help prevent blisters, and don’t keep bacteria (ant-stink).
#5 UV PROTECTION
Even on cloudy days and in the seemingly cover of trees, you can get burnt by the sun
#6 BUG REPELLANT
Bugs suck, but don’t let them ruin your hike. Pack bug repellant. You can even find clothing that includes bug repelling properties.
#7 PREPARE FOR THE UNEXPECTED
Even if the forecast calls for a warm dry day, does not necessarily mean you will be warm and dry. Pack a lightweight rain jacket (just in case) along with a dry tee shirt and extra pair of socks to change into if you get wet (from above OR below). Also pack a small first aid kit (you never know)
#8 REST OFTEN
Warm summer hikes can drain your energy and dehydrate you very quickly. Take it slow, rest often, hydrate regularly. Stop to enjoy every view.
#9 PACK LIGHT
Bring only the essentials. The lighter your load the easier you will move and less strain on your back and leg muscles.
#10 TELL SOMEONE WHERE YOU ARE GOING
You will be surprised how many frequent hikers get lost (or injured) on the trails they hike everyday.
AND LASTLY: LEAVE NO TRACE!
Bring your trash back with you and leave nature as you found it.