Today, an infection isn't usually too serious of a problem, with so many kinds of antibiotics available.
Was there any way to deal with infections in pre-modern times? Let's say before 1700.
Here are some methods that were used throughout history to fight infection.
Australian Aborigines discovered that eucalyptus and tea tree bark and leaves could ease certain infections. Other aboriginal societies used local herbs to help ease the symptoms of infection. This was typically tribal knowledge passed down through generations of healers.
As documented in the Bible, ancient Hebrews used isolation of infected persons, behavioral laws and such to limit exposure to pathogens in the general population. Divine inspiration or borrowing ideas from other, nearby, societies such as the Sumerians and Egyptians, you decide.
In India and China, herbal medicines were used to relieve infections. Often these were toxic compounds that contain potent alkaloids and heavy metals. Some would work against some infections, provided that they didn't kill the patient as well. Others weren't effective at all beyond a placebo effect. Some of these are still used today in traditional Chinese medicine.
The Romans had a herbal "wonder drug" called Silphium that seemed to help with many infections as well as being an abortifacient. The plant that produced it was driven into extinction. Romans also used vinegar and alcohols to disinfect wounds. Other herbal concoctions were around as well with varied effectiveness.
In the middle ages in Europe, medicine took a step back with leeching and other 'cures' related to superstitions, most notably humours. Also, herbal remedies from Roman times were still around to some extent.
Islamic doctors combined what they learned from the Greek and Roman traditions with ideas learned from India. These were also herbal remedies, some based on Afghan opium, and heavy metals, such as mercuric chloride. At one point, they probably had the most advanced medical treatment available in the world but then a lot of this knowledge was lost after the Islamic Golden Age.
Right around your cutoff date of 1700, quinine was brought from Peru to Europe. It was effective in treating malaria and some other ailments to some degree. Treatment with toxic alkaloids and heavy metals continued up until the early 20th century when antibiotics were discovered.
In Poland a traditional dressing for wounds was bread mixed with spider web, chewed before application.
During the plague years of the Thirteenth Century, towns excluded people that had visited plague cities from entering and ships were sometimes quarantined when entering port. Measures for containing plague inside towns included walling up of houses, inhabitants and all or burning of afflicted villages. Anyone who nursed a plague victim in some towns was quarantined for ten days. Barbara Tuchman's A Distant Mirror mentions these measures.