Topic summary
Blisters

Extracted from the Wikipedia article Blister.
Friction blisters
Blisters on feet can be prevented by wearing comfortable, well-fitting shoes and clean socks. Inherently ill-fitting or stiffer shoes, such as high heels and dress shoes, present a larger risk of blistering. Blisters are more likely to develop on skin that is moist, so socks that manage moisture or frequent sock changes will aid those with particularly sweaty feet. While exercising or playing sports, special sports socks can help keep feet drier and reduce the chance of blisters. Before going for a long walk, it is also important to ensure that shoes or hiking boots have been properly broken in.