Since its so hot you really need to stick with styles that allow your hair to be up. A ponytail with a poofy bump in the front, pigtails up high on the head, braided pig tails at the bottom of the scalp, a bun, just anything that gets your hair up because it will keep you cooler. Also since your outdoors do not use alot or any if you can products, it attracts mosquios and bees.
I think, since it is hot to have your hair either really lond that you are abel to do thoes messed up hair bun or a nice high up pony tail, or really short like sholder length. If your going to cut iit short thoe, don't get layers becuase short hair isint good with layers. the only thing close to layers that i would get would be that V-cut coming from the back to the front.
another hairstyle is called FRENCH BRAIDS. google a vedio about it. they have side french braids and pigtail french braids and ponytail french braid. also if you have bangs you can do something called a FRENCH TWIST on them. it looks really pretty. good luck.