 feeling very exhausted, almost feeling a little bit lightheaded or dizzy, you can jump right to that. And that's often what people will recognize as when they start to feel heat-related problems. When do you hit 911? Yeah, when you stop sweating. That's a major problem. Really? When you get to the point, yeah. What will happen is your body will start to go typically heat exhaustion. You're sweating. Your body's trying to actively cool itself.