Hypothermia

As the body temperature drops, the body begins to shiver to try and create more heat. That will be the first thing you will notice. As the temperature reaches a more dangerous level, your body may become weak, with symptoms of slurred speech, shallow breathing, and drowsiness. It is possible to get symptoms of confusion and losing consciousness. In children, it is important to note - their skin becomes bright red in the cold, unlike the blue colour in adults.

Extreme weather conditions which can happen in other countries and climates or immersion in cold waters such as lakes or rivers are common reasons for hypothermia. 

It can occur if you stay out in the cold too long, dress inappropriately for the weather, stay in wet clothes too long or live in poor housing conditions. These all lead to situations where your body loses heat faster than it can produce it.

Your age has an effect on your body's ability to regulate temperature. The elderly and the very young have difficulty retaining heat which puts them more at risk. There are also many medical conditions that can lead to hypothermia. Hypothyroidism, diabetes, anorexia nervosa and some neurological conditions impair your body's ability to regulate its temperature.

Medications too can have the same effect, such as antidepressants, antipsychotics, and sedative medications. Drugs and alcohol can cause your blood vessels to expand (vasodilate) which means heat is lost from the skin faster. They also impair your reasoning leading you to dress inappropriately for the weather. Passing out in the street when intoxicated from drugs or alcohol puts you at greater risk of hypothermia.