Put away notebooks, papers, and any other clutter that might pose a fire hazard. Avoid using a Bunsen burner below a shelf or other overhead equipment. In addition to wearing protective goggles and gloves, make sure your wardrobe is free of potential fire hazards. Tie back long hair, tuck in or remove loose clothing, and take off dangling jewelry.  Remember to always wear closed-toed shoes in the lab. Consider wearing a lab coat to cover any loose clothing. Before lighting the burner, know where to exit in case of an emergency, find the emergency gas switch, and locate the fire alarm. Note safety equipment, such as fire extinguishers and dry powder flame retardants. Hold the Bunsen burner only by the base or by the collar at the bottom of the barrel. After the burner is lit, the barrel itself will be too hot to handle. To reinforce safety habits, avoid touching the barrel even if the burner isn’t in use. Keep your eye on it at all times, and never leave the laboratory while it’s lit. If you are working on something for a moment that does not require the flame, turn it down to the coolest yellow flame (known as a safety flame).

===
Write a summary of the previous text in Chinese:
在干净整洁的环境中使用煤气喷灯。 戴上安全装备，将头发扎到脑后，松散的衣物也要扎好系紧。 找到安全设备、警铃，以及紧急出口。 只接触煤气喷灯的底座。 煤气喷灯点燃后，旁边一定要留人。