Since you said that lives are at risks in your implementation, i strongly suggests educating the users to use multiple tabs instead of clicking on some panic buttons.
My reasons being
- In times of 'emergency', how long does it take for the user to move their hands to the mouse (assuming they lifted their hands to type or touch their hair or whatever they wanted to do), let's assume it took them -> 0.5 seconds
- In your example site, the green bar is actually very small, to be frank, not everyone is very accurate with their hand, eyes coordination (moreover mouse cursor acceleration might differ between OS'es and User Profiles), the user has to move the mouse to the "Panic" button and click, unless they are professional FPS gamers, it's likely to take them another -> 1-2 seconds
- My last variable assumption is, if your script involves loading remote resources, for e.g. www.google.com, you can put lives at risk by assuming that the browser is
- Modern
- Has scripts enabled
- Network speed & latency is optimal
- Caches are primed.
If you are going to load remote resources, i suggests you to insert a div with z-index: -1 and some dummy web contents. On click, move their z-index higher to overlap everything on screen.
So if we assume you load a remote resource and with all the unknown variables, we can assume the time taken to be -> 0.5 - 10 seconds
If you are going to write a program that might kill someone, i strongly suggests you not to take the risk of doing something that might take 2 - 12 seconds to save them.
Educate your users by putting a banner with instructions
- Open a tab that wouldn't threaten their own lives (e.g. google.com, msn.com, yahoo.com)
- Open another tab with your site
- Navigate normally on your site
- In times of emergency, press Ctrl+W for Google Chrome, IE, Firefox, Opera (please confirm for other major browsers)
If you get the whole idea, press ctrl + w vs your planned solution, i can certainly guarantee that Ctrl+W is going to be faster.
