If the individual want's to do something that is unsafe or risky that is their choice and you must respect their rights but you have a duty of care and must do all that you can to keep them safe.
That is the dilemma.
You can carry out a risk assessment that involves the individual so that they fully understand the risk they are taking. If they still want to take the risk you make it as safe as possible for them. You have then done all that you can be expected to do under your duty of care.
Hope that helps