Carelessness is a failure to use the degree of attentiveness, caution and prudence that a reasonable person in the circumstances would exercise. In a legal context, people are held to a minimum required standard of use of reasonable care to avoid harm to others. When the failure to use reasonable care leads to harm, the actor may be lieble in negligence to the harmed person for damages.
Reasonable care is the degree of caution and concern an ordinarily prudent and rational person would use in similar circumstances. It is a standard used to determine a legal duty and whether such duty was fulfilled. Reasonableness is a subjective test used to determine negligence, meaning that a person failed to exercise reasonable care.
For example, a first aider, has a duty of care towards casualties to exercise reasonable care and skill in providing first aid treatment. The duty arises because of the first aider's knowledge and skills relevant to a medical emergency situation. If you choose to provide first aid assistance, you have a duty to use your knowledge and skills in a responsible way.
The court may examine issues to establish whether the first aider exercised reasonable care:
