Next, botulinum toxin A solution will be mixed per standard protocol in the dermatology clinic and will be applied and evenly spread over the palm that was randomized for treatment with botulinum toxin A. The other palm will be treated with a placebo (saline). This will be followed by occlusion with an occlusive wrap such as saran wrap, a silicone based gel, or glove. The subject will be asked to keep the saran wrap, silicone gel, or glove in place for 1 hour. Botulinum toxin A is an FDA approved product for the treatment of hyperhidrosis.