Even though it may be 100 degrees outside and all that gear can be heavy and uncomfortable, that's no excuse for not wearing it. All it takes is one trip to the ground and you'll appreciate the protection you get by wearing the right ATV safety equipment including a helmet, goggles, gloves, boots, and long pants/shirt.
The most basic piece of ATV safety equipment is protection for the most vulnerable part of your anatomy; your head. An injury to your head is much more likely if you fall off an ATV while not wearing a helmet. It is not required by law in all states to wear a helmet while riding an ATV, it is strongly encouraged.
There are good reasons you should wear gloves while you ride. Gloves are a key piece of ATV safety equipment. Gloves can protect your hands from flying gravel and rocks, a branch from a tree or bush you pass too closely by, and gloves help prevent your hands from getting too sore or callused. They also absorb a lot of vibration that transmits through the handlebars, making it more comfortable (and safe) to ride. A good pair of ATV gloves go a long way for comfort and safey.
If you get something in your eyes while you're riding your ATV, it's going to bring your trip to an abrupt ending. Eye protection is a must when it comes to ATV safety equipment for just about any type of motorsport, but especially something off-road and in groups where debris is almost always flying around. They work much better than sun-glasses because they are strapped to the helmet and because they keep out dust and debris from the sides.
Body armor can help protect your upper torso from larger rocks that might hit you. But more importantly, they will help protect you in case you are in an accident where the ATV lands on top of you. It can help protect your chest from getting crushed or punctured. A good chest protector is often over-looked as a piece of ATV safety equipment.
Long Sleeve Shirt and Pants
Having long pants and a long sleeve shirt on can be very uncomfortable, but it provides a great service as well by protecting your skin from scrapes cuts and abrasions. As with gloves, boots and goggles, long pants and shirts can protect you from branches and brush scraping you, as well as from gravel if you fall of and slide on the ground. ATV safety equipment doesn't always have to protect you in a crash, it can also protect you from the sun, wind and elements. Long sleeves and pants are a great example.