White willow bark is claimed in ThermoChrome promotions to reduce inflammation, relieve pain and swollen joints due to rheumatism and arthritis, and help neuralgia. These claims are probably true. White willow contains salicin which is converted in the body to salicylic acid, the same active ingredient that is in aspirin. However, unlike aspirin, white willow bark's label has no warning as FDA requires on aspirin. Aspirin labels warn that children should not take aspirin for chicken pox or influenza symptoms because of an association with Reyes syndrome; and, because white willow bark shares many of the same chemical properties and the same side effects as aspirin, white willow should also be avoided by aspirin-sensitive adults. Some stroke patients are also advised to avoid aspirin.