Look after yourself and the people around you. If you or someone near you needs help, find the nearest staff member, head to guest services, or go to the medical or first-aid tent.
Most Hardwater events are hosted at external venues, which means on-site safety, medical response, and emergencies are handled by the venue and the event's producers, they have trained staff on the ground for exactly this. Follow their direction, and look for posted signage when you arrive so you know where guest services and first aid are.
In a genuine emergency, contact venue security or local emergency services right away.