Clarksville, TN – A prolonged stretch of dangerous summer heat is headed for Clarksville and Montgomery County, with a Heat Advisory taking effect at 10:00am Tuesday and continuing through 9:00pm CT Thursday. Hot temperatures combined with high humidity can place additional stress on the body and increase the risk of heat exhaustion and heat stroke. Know the Signs of Heat IllnessIt is important to recognize the warning signs of heat exhaustion and heat stroke. Symptoms of heat exhaustion can include heavy sweating, weakness, dizziness, headache, nausea and muscle cramps. Heat stroke is a medical emergency and can involve confusion, loss of consciousness, seizures and extremely high body temperature.