Whilst incarnate we are not aware of what we do on an automatic basis energetically, because it is done subconsciously.
We are only aware of what we do energetically from a conscious basis. So consciously we know what we do deliberately through the energetic, but we are unaware of, and have no control over, what our subconscious is doing energetically.
Based upon this we are not aware of the full functionality of the energy exchanges we make on a minute by minute basis, which includes the giving and receiving of energy. Remember, we are only conscious of 10% of what we think and do whilst incarnate, which by and large ignores the energetic as it focuses on the physical environment.
People who know each other, work with each other, or, are intimate with each other constantly give and take energy from each other. Its a natural and normal function of what we are. So when we are ill it is a natural and automatic function to take energy from one who is close to us to assist in our healing process. This energy is usually given freely and automatically from the person whose energy is being requested.
The problem with this functionality occurs when the giver of the energy cannot afford to give any energy and the loss causes them to become depleted and therefore physically ill themselves.
In this instance the giver of energy needs to shield themselves in order to protect their own energies, allowing them to perform their physical tasks in support of their ill partner, supporting their commitments to them in the process whilst maintaining essential energy levels.
Note though that even advanced spiritualists do not always get energy from higher sources – especially when ill, and cannot state that they would never take energy from anyone else!