A headlamp, headlight, or head torch (UK) is a light source affixed to the head typically for outdoor activities at night or in dark conditions such as caving, orienteering, hiking, skiing, backpacking, camping, mountaineering or mountain biking.
[citation needed] Incandescent bulbs were used in headlamps until the introduction of white LEDs of sufficient brightness, with much lower power consumption and lifespan.
Battery-powered headlamps with incandescent bulbs were used until the advent of LED lamps with much higher efficiency and consequently longer battery life.
[citation needed] These included features such as spring-loaded contacts to automatically disconnect broken bulbs.
[4] Head lamps approved for use in coal mines are designed not to allow an internal spark to ignite flammable gas surrounding the headlamp.