The dry Winter air combined with heavy jackets can lead to plenty of surprises this time of year when you get shocked from car doors and other objects. The electro-static shock is relatively harmless but can cause a temporary pain to the human body. To electronics or the gas station fuel pump, that can be a different story. It is commonly recommended to ground yourself by touching a metal object before filling your car up or working with electronic components, such as inside your PC. That’s why they sell anti-static wrist straps and recommend their use to system builders.
This video includes some other tips about ESD: