Answer: Heart Attacks

The odds of surviving cardiac arrest drop 10 percent for every minute it takes for emergency responders to arrive on the scene and begin administering care. Plenty of people have basic first aid and CPR training that can help, but they have no idea somebody nearby is in distress. Sweden cleverly solved the dilemma of having slow ambulance responses in high-traffic areas like Stockholm and plenty of CPR trained but unaware people that could help by setting up an SMS network to alert them.

Whenever someone dials the emergency number 112, a text message is sent via the SMS network to all registered volunteers within 500 meters of their location. The system has proved so successful that 54 percent of the time the volunteers are on site performing CPR before the first responders. Through a combination of techniques (including the SMS alert system), the survival rate for cardiac arrest patients in the Stockholm area has risen from three percent to 11 percent in the past decade.