The Oklahoma State Department of Health  reminds residents that heat-related illness can range from heat cramps and heat exhaustion to hyperthermia (overheating) and heat stroke. Heat stroke occurs when the body is unable to cool itself sufficiently, and it often results in severe organ damage or even death. 

Closely monitor those who are more vulnerable. Infants, children, people older than 65 years of age, those with mental illness, outdoor workers and those with physical illnesses such as heart disease or high blood pressure should be closely observed.