Have you ever thought what you would do if you cut or burnt your hand seriously by accident when you were alone? Although first aid is generally thought of as being applied by others rather than the casualties themselves, it is also needed when the casualty is alone. “One hand, and you can do almost everything.” This phrase characterizes EmergenSee, a first aid kit designed to help people administer first aid themselves. When one hand is wounded, the tools are easy to operate using only the other hand. The kit not only benefits users who need to treat wounds when they are alone but also makes first aid easier to administer by all.