Do temperature changes affect our body function?

The human body has the ability to maintain its temperature despite the changes of the surrounding temperature. Because of this characteristic, humans are classified as warm-blooded. However our body temperature varies in range depending on sex, age, time of the day, exertion level, health status (such as illness and mensturation ), what part of the body the measurement is taken at, state of consciousness  ( sleeping, waking, sedated), and emotions. Human body temperature is kept in normal range by thermoregulation in which adjustment of temperature is triggered by the central nervous system.
Human body temperature on normal condition is considered to be 37.0°C when measured orally, but this normal value can fluctuate to 36.1°C when one just woke up in the morning to higher value of 37.2°C just before bedtime in the evening.
Hypothermia occurs when one’s body temperature drops to dangerously low levels. As a result the body temperature decreases and at 28.5°C the afflicted person appears pale and might have irregular heartbeat, unconsciousness normally occur when the body temperature gets lower than 26.7°C. at these temperature respiration also slows and become shallow  resulting to decrease in the delivery of oxygen to body tissues.

However no person always has exactly the same temperature at every moment of the day. Temperature cycles regularly up and down through the day controlled by the person’ circadian rhythm.  

In addition to this variation, our body fluctuates in response to the extremes of the surrounding. Foristance when temperature rise, the body reacts by increasing blood flow to the skin surface , taking the heat from within the body to the surface , this means sweat. As the sweat evaporates the body cools down. Body temperature more than 3.5°C above normal begin to interfere with bodily functions. Body temperature above 41.1°C can cause hyperthermia which are several conditions that occur when one’s heat regulation can’t handle the heat of the surrounding, and it can cause permernent brain damage especially to children.