Are you allowed to drive a car if you have a cold with a high fever?

It depends on how affected you are. It is prohibited to drive if you cannot drive in a safe manner due to illness.

The law equates driving dangerously due to illness with driving dangerously due to fatigue or the influence of alcohol or drugs.

Do not take chances – always contact your doctor before getting behind the wheel if you are unsure whether your medical condition is making you unfit for driving.