People who live on the upper floors of high-rise buildings are facing an invisible danger.

A new study has found that they appear to be less likely to survive cardiac arrest if they live anywhere above the third floor, and that risk only gets worse the higher up you go, according to a HealthDay News report.

Above the 16th floor, the study authors found that the survival rate is “negligible” — a surprising new find that could cause people to have second thoughts before taking that amazing view.

However, the reason why this is the case is actually somewhat obvious. For people who live that high up, it takes longer for first responders to get to them. In a cardiac event, time is of the essence, so even a couple minutes of delay can mean the difference between life and death.

Those suffering from cardiac arrest need to be defibrilllated, or have the heart shocked back into action. These shocks decrease in effectiveness the longer after the cardiac event takes place.

“As the number of high-rise buildings continues to increase and as population density rises in major urban centres, it is important to determine the effect of delays to patient care in high-rise buildings on survival after cardiac arrest,” said Ian Drennan, a paramedic with York Region Paramedic Services, in a statement.

The authors added in the statement: “The 911 response time, from emergency activation to arrival of first responders on scene, will remain relatively constant, so long as traffic patterns do not change; however, the time from arrival on scene to initial patient contact may increase as more of the population comes to live at or above the third floor. Thus, 911 response time may diminish in importance as a determinant for survival, whereas the time to patient contact may become more important in predicting who lives and who dies after out-of-hospital cardiac arrest.”