Ticks are a source of Lyme disease, and should be removed from your skin as soon as possible. Do so using fine-tipped tweezers to firmly grasp the tick as close to its head/mouth as possible (don't use bare hands; if nothing else is available, protect them with gloves or tissue paper), and — with a steady motion — pull the tick's body straight out (no twisting or wiggling), away from your skin. Then clean the skin with rubbing alcohol (if available), followed with soap and warm water. If possible, freeze the tick (in a jar or bag), in case it's needed for later identification.
Avoid crushing the tick's body. Do not be alarmed if the tick's mouthparts remain in the skin, as once they are detached from the body of the tick, they can no longer transmit the Lyme disease bacteria.
Don't use petroleum jelly, heat, nail polish, or other methods to remove ticks.