The Heat Index Chart

The heat index also applies to shady, light wind conditions, so it feels even hotter than the heat index if a person is in direct sun. In the midst of a hot, dry, wind a person would also feel hotter than the heat index value due to the wind effects.Excessive and dangerous heat indices occur mostly during the summer months with the abundance of moisture and increased heat.

Apparent Temperature Readings

• Caution -- 85 to 94°F -- physical activity may cause fatigue
• Extreme Caution -- 95 to 105°F -- possible heat cramps and/or heat exhaustion with prolonged exposure
• Danger -- Above 105°F -- possible heat stroke with prolonged exposure; heat exhaustion and heat cramps likely