Received TDAP vaccine IM to the left deltoid muscle. Venipuncture for labs was then performed. Lab draw was completed and he complained of feeling hot. His skin then became clammy and he appeared to black out for approx 1 second. He immediately regained consciousness. He was diaphoretic. He was placed in supine position on exam table. He remained alert. Blood pressure was 91/54. BP was 129/90 prior to TDAP dose. He then c/o feeling dizzy, lightheaded, nauseous and reported a stomach ache. He was allowed to rest and provided a gatorade to hydrate himself. After approximately 25 minutes of monitoring he reported feeling better but felt drained with residual nausea. Repeat BP 136/91.