Glossary H

Deutsch: Kopfhörer / Español: Auriculares - Auriculares / Português: Fones de ouvido - Fones de ouvido / Français: Casque audio - Casque audio / Italiano: Auricolari - Auricolari
Headphones are a pair of small loudspeakers that are designed to be held in place close to a user's ears. They are also known as earspeakers, earphones or, colloquially, cans. The alternate in-ear versions are known as earbuds or earphones.

Deutsch: Gefährdung / Español: Peligro / Français: Danger / Italiano: Pericolo
A hazard is a situation that poses a level of threat to life, health, property, or environment. Most hazards are dormant or potential, with only a theoretical risk of harm; however, once a hazard becomes "active", it can create an emergency situation. A hazardous situation that has come to pass is called an incident. Hazard and possibility interact together to create risk.

Deutsch: Laubholz / Português: Madeira de lei / Français: Bois dur

Hardwood is wood from angiosperm trees (more strictly speaking non-monocot angiosperm trees). It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.

Deutsch: Gesundheitswesen / Español: Atención Médica / Português: Cuidados de Saúde / Français: Soins de Santé / Italiano: Assistenza Sanitaria /

Health care or healthcare is the improvement of health via the prevention, diagnosis, treatment, amelioration, or cure of disease, illness, injury, and other physical and mental impairments in people. Health care is delivered by health professionals and allied health fields. Medicine, dentistry, pharmacy, midwifery, nursing, optometry, audiology, psychology, occupational therapy, physical therapy, athletic training, and other health professions are all part of health care.

Deutsch: Krankenhaus / Español: Hospital / Português: Hospital / Français: Hôpital / Italiano: Ospedale

A hospital is a health care institution providing patient treatment by specialised staff and equipment.
Hospitals are usually funded by the public sector, by health organisations (for profit or nonprofit), health insurance companies, or charities, including direct charitable donations. Historically, hospitals were often founded and funded by religious orders or charitable individuals and leaders. Today, hospitals are largely staffed by professional physicians, surgeons, and nurses, whereas in the past, this work was usually performed by the founding religious orders or by volunteers.

Deutsch: Polyethylen / Español: Polietileno de alta densidad / Français: Polyéthylène haute densitê / Italiano: Polietilene ad alta densità
High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a polyethylene thermoplastic made from petroleum. Known for its large strength to density ratio, HDPE is commonly used in the production of plastic bottles, corrosion-resistant piping, geomembranes, and plastic lumber. HDPE is commonly recycled, and has the number "2" as its recycling symbol.

Deutsch: Heizung
HVAC (heating, ventilating, and air conditioning; also heating, ventilation, and air conditioning) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. The heat generation is done by a heater.

HCL stands for Hydrochloric Acid, which is a strong, corrosive acid that is commonly used in various industrial applications.