- Eye protection. Plastic safety glasses or something like that to prevent dirt getting into your eyes.
- Dust mask or respirator. You don't want to breathe in the dust/bad air in that area.
- Headlamp. This allows you to see much better in there and both hands to work with.
When I go into crawl spaces I use old clothes and sneakers that I consider disposable. Then I just throw them in the trash once the work is complete.