First Aid is defined as:
" Procedures used in an emergency to help a wounded or ill patient before the arrival of a doctor or admission to hospital", Oxford Medical Dictionary.
A key aspect of First Aid is that one cannot predict when it will be required and in what form. That is one reason why many therapists and organisers of sports and other activities choose to be trained in First Aid even if there is no formal requirement that they do so. There are many circumstances such as in work places and premises open to the general public, when there is a formal requirement to have both personnel trained in First Aid and suitable First Aid Kits and/or equipment available at all times. (Legal and other regulatory requirements vary according to jurisdiction. If such rules might apply to you or your business or organisation check the rules that apply in your country, state or other designation of locality.)
Whether or not there is any legal requirement to have First Aid facilities available, it is widely considered to be a good idea.
Many people keep appropriate items convenient for emergency use in kitchens, garages or workshops, cars, or other vehicles.