Respuesta :

angelinaalaya
No it doesn't have to be unless if you are referring to it as a proper noun but in this case, "I got out the first aid kit and handed it to dad." 
Greenleafable
It really depends on the context.
If you are using it in a noun phrase - first aid kit - you don't have to capitalize it. But, if you are saying - Certified in First Aid, then you would capitalize it, because it is the name of an assistance.