Safety should always be your top priority whenever you have a roofing project. Falls account for a large majority of serious injuries and deaths in construction, and even experts die from falls on occasion.
However, professional contractors have the skills and equipment to mount a roof safely, whether your home has one floor or many. They know how use a harness, attach a rope grab and install temporary guardrails. They can properly handle common roofing equipment, such as circular saws and shingle shears. And they wear protective clothing to reduce their risk of injury.
Unless you have access to all the right equipment and have special training in roof repair, you’ll stay safer if you keep both feet on the ground.