Normal body temperatures in cats range between 100 - 102.5°F (37.7 - 39.1°C). The body regulates its temperature (known as thermoregulation) by a number of measures and for a number of reasons.
When an infection occurs, the body will often increase the internal temperature as a way to fight off and kill the infectious organism, this is known as pyrexia.
Thermoregulation refers to the control of the body temperature as a result of external factors such as an increase or decrease in temperature. This occurs by:
Change in location - Moving to a shady spot if it's hot, moving to a sheltered spot, or into the sun if it's cold.
Vasoconstriction or vasodilation - Narrowing or widening of the blood vessels to restrict or increase blood flow. Blood carries heat, which is then when it reaches the surface of the skin. So on hot days, the blood vessels dilate to increase blood flow to the skin, on cold days they constrict to reduce heat loss.
Hairs - Hairs stand on end when the temperature falls, this improves the insulating properties of the skin and coat.
Shivering - When the temperature drops and the above methods are no longer effective, your cat will shiver. This occurs when muscles begin to shiver slightly in order to produce warmth by expending energy. Shivering can also occur in response to fever.
Sweating - This isn't as important in cats as it is in humans. Cats do sweat a little through their paws.
Cat has high temperature:
There are two causes of a high temperature in cats. Fever (pyrexia) or hyperthermia.
Fever (pyrexia) is usually the result of an infection. The body increases the internal temperature in order to fight off the infection.
Hyperthermia occurs when the external temperature is higher than your cat's body temperature and he is unable to bring the temperature down by thermoregulation. For example, a cat locked in a car on a warm day is at great risk of developing hyperthermia. This is a life-threatening condition and requires urgent veterinary attention.
Cat has low temperature:
This is known as hypothermia and may be caused by the external temperature being too low and once again, thermoregulation being unable to maintain the body temperature at safe levels. It can occur if your cat is in the cold for a period of time.
Young kittens are very poor at maintaining body temperature, therefore, it is important for the pet owner to be aware of this and maintain a steady temperature for them.
How to take your cat's temperature:
To take the temperature with a mercury thermometer you will need:
Have your cat on a firm surface such as a dining table and have your helper hold him by the scruff of the neck so that he can't run away.
Shake the thermometer firmly until it drops to 96°F (35.5C).
Lubricate the bulb tip with a little petroleum jelly, lift the base of the tail and gently slide it into your cat's rectum until half of it is inside. Keep it in for three minutes, withdraw and check the reading.
You should seek veterinary attention if your cat's temperature is under 99°F (37.2°C) or over 104°F (40°C).
How to reduce a fever in a cat:
If your cat only has a moderate temperature and seems otherwise well, you can try to reduce it by using fans to cool him off and/or offering him cool water.
Don't give your cat a bath, this will make the situation worse by trapping the water in the coat, which acts as insulation.
How to treat hyperthermia (heat stroke):
If you suspect your cat has hyperthermia, seek veterinary attention immediately. Do not attempt to treat at home.