While no account is generally taken of the peculiarities of the defendant, apart from his or her age, the peculiarities of the claimant are commonly relevant. If the claimant is known to be particularly vulnerable for any reason, this is a relevant factor in determining the appropriate level of care.
Paris v Stepney BC  1 All ER 42, HL
P was a garage mechanic, who had lost the sight of one eye during the war. In order to loosen a stiff bolt he struck it with a hammer; a piece of metal flew off and (because he was not wearing goggles) struck him in his good eye, causing him to become totally blind. The probability of such an event was very small, but its consequences were very serious, and the House of Lords held that his employers, knowing of his disability, should have taken extra care to provide goggles for him. The more serious the possible damage, said Lord Morton, the greater the precautions that should be taken.
Haley v London Electricity Board  3 All ER 185, HL
Workmen from the Electricity Board were preparing to carry out work on underground cables; they dug a hole, and in order to give warning of the danger (before the permanent barriers arrived) they laid a long-handled hammer across the pavement. P, a blind man, walked along the pavement on his way to work; he tripped over the hammer and was injured. The House of Lords said DD were negligent; they had given adequate warning to sighted people, but it was common knowledge that large numbers of blind people walked unaided along pavements and the duty of care extended to them as well.
Morrell v Owen (1993) Times 14/12/93, Mitchell J
At a sports event for disabled athletes, archery and discus activities took place in the same hall, separated by a curtain. Anyone entering or leaving the archery section had to negotiate a route past this curtain, which billowed out from time to time when struck by a discus. P was an archer, and was close to the curtain when a discus struck her head (through the curtain) and caused brain damage. The judge found as a fact that she had not been adequately warned of the danger, and awarded damages against the coaches in the two activities. Obiter, the organisers of and coaches at a sports event for disabled persons had a greater duty of care than those who organised events for able-bodied athletes; they should have instructed the participants in appropriate safety procedures, made provision for safe passage into and out of the practice area, and provided someone to watch over the movements of the disabled.
Walker v Northumberland CC  1 All ER 737, Colman J
P was a senior social worker who suffered a nervous breakdown, apparently from overwork. He returned to work but suffered another more serious breakdown within a year, the workload being no less. His claim for damages against his employer succeeded: the duty to provide a safe system of work, said the judge, extended just as much to psychiatric damage as to physical injury. The first breakdown may not have been foreseeable, but the second certainly was, and DD had taken manifestly inadequate measures to protect P's health.