P's son was injured when the son lost control of his motorcycle after striking debris in the road. The son was wearing a helmet manufactured by D. P, the father, filed suit against D alleging that the helmet was defectively designed and manufactured and that D failed to warn that the helmet would not afford any significant protection from certain reasonably foreseeable impacts. The helmet contained a warning label inside of the helmet, stating in substance that 'some reasonably foreseeable impacts may exceed this helmet's capability to protect against severe injury or death.' It also had a consumer notice that informs the purchaser that 'your helmet is the single most important piece of safety equipment you own and should be treated as such.' The notice further stated that 'NO HELMET, including your AGV helmet, can protect the wearer against all foreseeable impacts' and that 'NO WARRANTY OR REPRESENTATION IS MADE AS TO THIS PRODUCT'S ABILITY TO PROTECT THE USER FROM ANY INJURY OR DEATH. THE USER ASSUMES ALL RISKS.' D moved for summary judgment. P offered the deposition testimony of Dr. Joseph L. Burton who conducted impact tests which found that no motorcycle helmet marketed today provides any assurance of protecting the wearer from facial or brain injury at speeds of 30 or 45 miles an hour. He opined that the average purchaser of a helmet would not know these facts. D got the summary judgment on the failure to warn theory on the ground that it was open and obvious that the helmet would not protect an operator traveling at 30 to 45 miles an hour. P appealed.