Increased Temperature
June 25th, 2019
Increased Body Temperature
Increased temperature most often is related to fevers, however it is important to consider non-inflammatory causes of hyperthermia.
Classification
- Fever - 37.5 - 38.3°C
- Hyperthermia - 38.4 - 39.9°C
- Hyperpyrexia - 40 - 41°C
- Extreme hyperpyrexia - >41.5°C
Fevers occur when the body's 'set point' of temperature is set to a higher level than normal. This results in responses aimed at increasing body temperature, including vasoconstriction and shivering.
Non-inflammatory hyperthermia occurs when there is an imbalance in heat production and heat dissipation.
Causes of Increased Body Temperature
Fever
- Infection - bacterial, protozoal, fungal, viral
- Auto-immune conditions - rheumatoid arthritis, SLE, thyroiditis
- Thromboembolism - DVT / PE
- Metabolic disorders - gout
- Transfusion reactions
- Abnormal hypothalamic function - stroke, encephalitis, head trauma
Non-Inflammatory Causes
- Excessive heat production - exertion, thyrotoxicosis, phaeochromocytoma, status epilepticus, tetany
- Poor heat dissipation - heat stroke, dehydration, autonomic dysfunction, excessive clothing
- Drug-induced - aspirin, stimulants, anticholinergics
- Malignant hyperthermia (rare reaction to inhaled anaesthetics)
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