Do keep a fire extinguisher and first aid kit within easy reach.Do wear safety glasses or goggles when cutting, drilling, grinding, prying or recharging the A/C system. If you wear glasses for the sake of vision, then they should be made of hardened glass that can serve also as safety glasses, or wear safety goggles over your regular glasses.Do shield your eyes whenever you work around the battery. Batteries contain sulfuric acid. In case of contact with the eyes or skin, flush the area with water or a mixture of water and baking soda and get medical attention immediately.Do use safety stands (jackstands) for any under-car service. Jacks are for raising vehicles; safety stands are for making sure the vehicle stays raised until you want it to come down. Whenever the vehicle is raised, block the wheels remaining on the ground and set the parking brake.Do use adequate ventilation when working with any chemicals. Asbestos dust resulting from brake lining wear causes cancer.Do disconnect the negative (-) battery cable when working on the electrical system.Do follow manufacturer's directions whenever working with potentially hazardous materials. Both brake fluid and antifreeze are poisonous if taken internally.Do properly maintain your tools. Loose hammerheads, mushroomed punches and chisels, frayed or poorly grounded electrical cords, excessively worn screwdrivers, spread wrenches (open end), cracked sockets, slipping ratchets, or faulty droplight sockets can cause accidents.Do use the proper size and type of tool for the job being done.Do when possible, pull on a wrench handle rather than push on it, and adjust your stance to prevent a fall.Do be sure that adjustable wrenches are tightly adjusted on the nut or bolt and pulled so that the face is on the side of the fixed jaw.Do select a wrench or socket that fits the nut or bolt. The wrench or socket should sit straight, not cocked.Do strike squarely with a hammer; avoid glancing blows.Do set the parking brake and block the wheels if the work requires that the engine be running.