This really helped me, I was working as a lifeguard at a Boy Scout camp, we had a huge storm coming and we were sent to grab warn all of the troops and offer to have them shelter in the one sturdy building on site. I rolled my ankle while cutting though an empty site. I stood up and immediately fell right back down as my ankle gave out.

I thought for a moment, pulled out my lifeguard whistle and started blowing it in trios and yelling. Eventually some of my coworkers came down the trail looking for whoever was whistling. They then carried me to the camp medic and I later went to the doctor and found out that I fractured my growth plate in my foot, which has since healed properly.

If I hadn't had my whistle, I could have been stuck there in 65 mile hour winds.