Cold in the context of "Winter"

A crocodile (family Crocodylidae) or true crocodile is a large, semiaquatic reptile that lives throughout the tropics in Africa, Asia, the Americas and Australia. The term "crocodile" is sometimes used more loosely to include all extant members of the order Crocodilia, which includes the alligators and caimans (both members of the family Alligatoridae), the gharial and false gharial (both members of the family Gavialidae) as well as other extinct taxa.

Crocodile size, morphology, behaviour and ecology differ among species. However, they have many similarities in these areas as well. All crocodiles are semiaquatic and tend to congregate in freshwater habitats such as rivers, lakes, wetlands and sometimes in brackish water and saltwater. They are carnivorous animals, feeding mostly on vertebrates such as fish, reptiles, birds and mammals, and sometimes on invertebrates such as molluscs and crustaceans, depending on species and age. All crocodiles are tropical species that, unlike alligators, are very sensitive to cold. Many species are at the risk of extinction, some being classified as critically endangered.

Goose bumps (in American English), goose pimples (in British English), or goosebumps are the bumps on a person's skin at the base of body hairs which may involuntarily develop when a person is tickled, cold or experiencing strong emotions such as fear, euphoria or sexual arousal.

The formation of goose bumps in humans under stress is considered by some to be a vestigial reflex, though visible piloerection is associated with changes in skin temperature in humans. The reflex of producing goose bumps is known as piloerection or the pilomotor reflex, or, more traditionally, horripilation. It occurs in many mammals; a prominent example is porcupines, which raise their quills when threatened, or sea otters when they encounter sharks or other predators.

Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with body temperature exceeding the normal range caused by an increase in the body's temperature set point in the hypothalamus. There is no single agreed-upon upper limit for normal temperature: sources use values ranging between 37.2 and 38.3 °C (99.0 and 100.9 °F) in humans.

The increase in set point triggers increased muscle contractions and causes a feeling of cold or chills. This results in greater heat production and efforts to conserve heat. When the set point temperature returns to normal, a person feels hot, becomes flushed, and may begin to sweat. Rarely a fever may trigger a febrile seizure, with this being more common in young children. Fevers do not typically go higher than 41 to 42 °C (106 to 108 °F).

Mountain warfare or alpine warfare is warfare in mountains or similarly rough terrain. The term encompasses military operations affected by the terrain, hazards, and factors of combat and movement through rough terrain, as well as the strategies and tactics used by military forces in these situations and environments.

Mountain ranges are of strategic importance since they often act as a natural border and may also be the origin of a water source such as the Golan Heights. Attacking a prepared enemy position in mountain terrain generally requires a greater ratio of attacking soldiers to defending soldiers than a war conducted on level ground. Mountains present natural hazards such as lightning, strong gusts of wind, rockfalls, avalanches, snowpacks, ice, extreme cold, and glaciers with their crevasses; in these ways, it can be similar to cold-weather warfare. The generally uneven terrain and the slow pace of troop and material movements are additional threats to combatants. Movement, reinforcements, and medical evacuation up and down steep slopes and areas in which even pack animals cannot reach involves an enormous exertion of energy.

Hardiness of plants describes their ability to survive adverse growing conditions. It is usually limited to discussions of climatic adversity. Thus a plant's ability to tolerate cold, heat, drought, flooding, or wind are typically considered measurements of hardiness. Hardiness of plants is defined by their native extent's geographic location: longitude, latitude and elevation. These attributes are often simplified to a hardiness zone. In temperate latitudes, the term most often describes resistance to cold, or "cold-hardiness", and is generally measured by the lowest temperature a plant can withstand.

Hardiness of a plant may be divided into two categories: tender, and hardy. Tender plants are those killed by freezing temperatures, while hardy plants survive freezing—at least down to certain temperatures, depending on the plant. "Half-hardy" is a term used sometimes in horticulture to describe bedding plants which are sown in heat in winter or early spring, and planted outside after all danger of frost has passed. "Fully hardy" usually refers to plants being classified under the Royal Horticultural Society classifications, and can often cause confusion to those not using this method. When this distinction is made a fully tropical plant that requires hot temperatures to grow and display is termed a "tender" plant.

Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non-striated, so-called because it has no sarcomeres and therefore no striations (bands or stripes). It can be divided into two subgroups, single-unit and multi-unit smooth muscle. Within single-unit muscle, the whole bundle or sheet of smooth muscle cells contracts as a syncytium.

Smooth muscle is found in the walls of hollow organs, including the stomach, intestines, bladder and uterus. In the walls of blood vessels, and lymph vessels, (excluding blood and lymph capillaries) it is known as vascular smooth muscle. There is smooth muscle in the tracts of the respiratory, urinary, and reproductive systems. In the eyes, the ciliary muscles, iris dilator muscle, and iris sphincter muscle are types of smooth muscles. The iris dilator and sphincter muscles are contained in the iris and contract in order to dilate or constrict the pupils. The ciliary muscles change the shape of the lens to focus on objects in accommodation. In the skin, smooth muscle cells such as those of the arrector pili cause hair to stand erect in response to cold temperature and fear.