This is normal. They're like shower caps. I use them for work lamps. Another reviewer mentioned that the fabric of the sock comes into contact with the lightbulb and the contact will turn brown over time (which is also a potential fire hazard). To avoid this I used several small binders. Clips for attaching rubber bands to the edge of work lights (first photo). This gave me more loose fabric in front of the bulb (second photo) to avoid any contact. I also use LED bulbs that run at a much lower temperature.