Does drinking fluids worsen a heat stroke?

Kind of: To the extent that trying to get someone to ingest fluid delays provision of the aggressive therapy required for the medical emergency that is heat stroke then yes, such a delay can worsen things. After you call 911 while waiting for the paramedics, you can try to cool the patient by immersing in cool water. Trying to force down fluids in a victim with diminished alertness might cause aspiration.

No. Heat Stroke!: Fluids help. Heat stroke is the most serious form of heat injury and is considered a medical emergency. If you suspect that someone has heat stroke -- also known as sunstroke -- call an ambulance immediately and give first aid until paramedics arrive. http://www.webmd.com/a-to-z-guides/heat-stroke-symptoms-and-treatment#1