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. 

The OSDH offers this tip for preventing a heat-related illness:

Stay indoors. Stay in an air-conditioned place. If your home is not air-conditioned, visit the mall or public library, or contact the local health department for the location of a heat-relief shelter in the area.