1. What is the Heat Index?

The Heat Index (HI) is a measure that combines air temperature and relative humidity to determine the human-perceived equivalent temperature. It indicates how hot it feels when humidity is factored in with the actual air temperature.

2. How Does the Calculator Work?

The calculator uses the NOAA Heat Index equation:

Where:

• \( T \) — Temperature in degrees Fahrenheit
• \( RH \) — Relative humidity percentage

Explanation: The equation accounts for how humidity affects the body's ability to cool itself through perspiration.

3. Importance of Heat Index Calculation

Details: The heat index is crucial for assessing heat stress risk, planning outdoor activities, and implementing heat safety measures in workplaces.

4. Using the Calculator

Tips: Enter temperature in °F and relative humidity as a percentage (0-100). The calculator is valid for temperatures above 80°F.

5. Frequently Asked Questions (FAQ)

Q1: Why is heat index important?
A: It helps predict heat-related illnesses by showing how temperature and humidity combine to affect the human body.

Q2: What are dangerous heat index levels?
A: 80-90°F: Caution; 90-103°F: Extreme Caution; 103-124°F: Danger; 125°F+: Extreme Danger.

Q3: Does wind affect heat index?
A: The standard formula doesn't account for wind, but breezes can make it feel slightly cooler than indicated.

Q4: Why does humidity make it feel hotter?
A: High humidity slows sweat evaporation, reducing the body's ability to cool itself.

Q5: Can heat index be below the actual temperature?
A: No, the heat index equals the actual temperature at 0% humidity and increases as humidity rises.