La hipotermia

Hypothermia is a condition in which core temperature drops below that required for normal metabolism and body functions which is defined as 35.0 °C (95.0 °F). Body temperature isusually maintained near a constant level of 36.5–37.5 °C (98–100 °F) through biologic homeostasis or thermoregulation. If exposed to cold and the internal mechanisms are unableto replenish the heat that is being lost, a drop in core temperature occurs. As body temperature decreases, characteristic symptoms occur such as shivering and mental confusion.Hypothermia is the opposite of hyperthermia which is present in heat exhaustion and heat stroke.
Causes
Hypothermia usually occurs from exposure to low temperatures, and isfrequently complicated by alcohol. Any condition which decreases heat production, increases heat loss, or impairs thermoregulation, however, may contribute.[26] Thus, hypothermia riskfactors include: any condition that affects judgment (hypoglycemia), the extremes of age, poor clothing, chronic medical conditions ( such as hypothyroidism and sepsis ),substance abuse, homelessness, and living in a cold environment.[27][28] Hypothermia also occurs frequently in major trauma.
Hyperthermia is an elevated body temperature due to failedthermoregulation. Hyperthermia occurs when the body produces or absorbs more heat than it can dissipate. When the elevated body temperatures are sufficiently high, hyperthermia is amedical emergency and requires immediate treatment to prevent disability and death.
Hot, dry skin is a typical sign of hyperthermia.[8] The skin may become red and hot as bloodvessels dilate in an attempt to increase heat dissipation, sometimes leading to swollen lips. An inability to cool the body through perspiration causes the skin to feel dry.