The effects of extreme heat on your body

(KYMA, KECY/CNN) - Millions of Americans face extreme temperatures and of that, heat is the number one killer in natural disasters.

The combination of high temperatures and high humidity creates the right condition for a heat emergency," explained Dr. Thomas Waters of the Cleveland Clinic.

Heatstroke and heat exhaustion are common heat-related conditions.

Someone suffering from a heatstroke may either sweat a lot or not at all, then becoming confused or pass out.

If a body loses too much salt water then heat exhaustion occurs, with symptoms including nausea dizziness, irritability, thirst, headache and high body temperature.

"If somebody notices that in somebody that they're in the heat with they need to take action right away and seek help," said Dr. Waters.