Final answer:
When driving in heavy fog, reduce speed and use low beam headlights or fog lights to improve visibility; avoid high beams which can reflect back and worsen visibility. Never look directly at bright lights to protect your eyesight.
Step-by-step explanation:
When driving in heavy fog, you should greatly reduce your normal speed to enhance safety, as low visibility conditions substantially increase the risk of accidents due to reduced reaction times and difficulty in judging the speed and distance of other vehicles. It is recommended to use your car's low beam headlights or fog lights if available, as high beams can reflect off the fog and create a "white wall" effect, further impairing visibility. Always make sure that your headlights are clean and in working order before driving in foggy conditions.
It is also important to observe and follow any additional safety protocols and guidelines specific to your location or vehicle. Moreover, as the instruction warns, one should never look directly at very bright light as it could cause damage to your eyesight or even temporary blindness, which is particularly dangerous when driving.