About

In clinical diagnostics and home care, accurate temperature interpretation is vital. A raw number is often insufficient without context; a reading considered a low-grade fever in an adult may indicate a serious infection in an infant. This Clinical Triage Assistant goes beyond simple arithmetic conversion. It integrates pediatric and geriatric reference standards to provide immediate, context-aware feedback.

The tool accounts for the non-linear nature of biological thermoregulation. It visualizes the transition from Hypothermia to Hyperpyrexia using a dynamic color-coded spectrum, allowing users to assess urgency instantly. Designed for medical staff, parents, and researchers, this system eliminates the risk of conversion errors during critical decision-making moments, such as determining antipyretic dosages or identifying sepsis protocols.

Formulas

Temperature conversion is a linear algebraic transformation. The relationship between the scales is defined by the freezing and boiling points of water at 1 atmosphere of pressure.

1. Celsius to Fahrenheit:

F = (C × 1.8) + 32

2. Fahrenheit to Celsius:

C = F − 321.8

3. Celsius to Kelvin (Scientific):

K = C + 273.15

Note: The Kelvin scale starts at Absolute Zero (0 K), meaning there are no negative numbers in Kelvin physics. In medical practice, ΔT of 1°C is equal to 1K.

Reference Data

Condition / State	Core Temp (°C)	Core Temp (°F)	Physiological Response & Clinical Actions
CRITICAL HYPOTHERMIA ZONE
Deep Hypothermia	< 28.0	< 82.4	Loss of consciousness, risk of ventricular fibrillation, no shivering. Immediate emergency rewarming required.
Moderate Hypothermia	28.0 - 32.0	82.4 - 89.6	Stupor, hyporeflexia, decreased heart rate (HR) and respiratory rate. Paradoxical undressing may occur.
Mild Hypothermia	32.1 - 35.0	89.8 - 95.0	Intense shivering, vasoconstriction (pale/blue skin), hypertension, tachypnea.
NORMAL REGULATION ZONE
Normothermia (Adult)	36.1 - 37.2	97.0 - 99.0	Optimal enzymatic activity. Follows circadian rhythm (lowest 4 AM, highest 6 PM).
Normothermia (Infant)	36.6 - 37.5	97.9 - 99.5	Higher metabolic rate generates more heat. Infants have poor thermoregulation.
PYREXIA (FEVER) ZONE
Low-Grade Fever	37.3 - 38.0	99.1 - 100.4	Mild immune response. Monitor hydration. Check for local inflammation.
Significant Fever	38.1 - 39.0	100.6 - 102.2	Common in viral/bacterial infections. Chills, malaise, anorexia. Antipyretics often indicated.
High Fever	39.1 - 40.5	102.4 - 104.9	Severe infection risk. Delirium possible. Warning zone for febrile seizures in children.
CRITICAL HYPERPYREXIA ZONE
Hyperpyrexia	> 40.6	> 105.1	Proteins begin to denature. Risk of permanent brain damage, organ failure, and death.
MEASUREMENT SITE ADJUSTMENTS (RULE OF THUMB)
Axillary (Armpit)	Add +0.5°C (+1.0°F) to estimate Core Temperature.
Rectal	Subtract -0.5°C (-1.0°F) to estimate Oral Temperature.

Frequently Asked Questions

Medical urgency depends on age. 1) Infants < 3 months: Any temp > 38.0°C (100.4°F) requires immediate emergency care. 2) Children 3-6 months: > 39.0°C (102.2°F). 3) Adults: > 40.0°C (104°F) or if the fever lasts more than 48-72 hours. Always consult a doctor if fever is accompanied by stiff neck, confusion, or rash.

Peripheral temperatures (skin, armpit, forehead) are usually cooler than Core Temperature (blood, organs). An armpit (axillary) reading is typically 0.5°C to 1°C (1-2°F) lower than a rectal or oral reading. This tool's reference table provides adjustment rules for different sites.

Hyperpyrexia begins at 41.5°C (106.7°F). At this level, the body's thermoregulatory system fails, and cellular proteins can begin to denature (break down), leading to irreversible organ damage. This is distinct from a controlled fever fighting an infection.

Shivering (rigors) usually indicates the temperature is rising. The hypothalamus has reset the body's "thermostat" to a higher setting, and the body shivers to generate heat to reach that new target. Sweating indicates the fever is breaking (defervescence) and the body is cooling down.

The "37°C standard" was set in 1868. Modern research shows average human body temperature has dropped slightly to roughly 36.6°C (97.9°F) due to lower metabolic rates and less chronic infection in the population. "Normal" is a range, not a single number.