 You're forgetting to take something on your hike that could save your life. Bear encounters like this one are increasing in places all over the country, so here's what to do if you come face to face with one. Back away slowly. Running can activate their chase instinct. Yell, hey bear! While raising your arms and making yourself big. If those don't work, let's hope you thought ahead and brought bear spray. It's 90% effective at deterring a bear that's behaving strangely. All you have to do is keep it somewhere accessible, remove the safety, point it towards the bear just lower than its head, and spray until it starts to retreat.