Hypothermia/A temperature of 93.7 orally/temperature was 92.7/went down to 93.2 degrees; Chills; The arm he received the injection in was tender however progressed to mild to moderately painful/arm was suddenly painful; Shaking; Injection site tenderness; This is a spontaneous report from a contactable physician (patient). A 77-year-old male patient received the first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE; lot: EL9262, expiry: unknown), via an unspecified route of administration in the left arm on 26Jan2021 15:30 at a single dose for protection from the virus at the Physician Office. Medical history included type 2 diabetes mellitus from 2011 and ongoing. The patient also thought he had a Covid respiratory infection in Feb2020. He had a prolonged moderate to severe respiratory infection. He thought at first that he had the flu, but he had a flu shot. He thinks he had Covid. He had antibody studies in May2020 (last spring) that were negative. The patient has no concomitant medications. The patient previously had influenza vaccine (flu shot). The patient reported hypothermia after getting the first dose of the Pfizer Covid 19 vaccine. On the same day of vaccination (26Jan2021), he had injection site tenderness. The next day, (27Jan2021), his arm was suddenly painful; he began to have chills 29 hours after receiving the vaccine (27Jan2021) and was shaking. He also had a temperature of 93.7 orally, confirmed with two different digital thermometers. He took his temperature with a new electronic thermometer that he purchased at a pharmacy. His temperature was 92.7 on 27Jan2021. He repeated it with another electronic thermometer. The first evening (27Jan2021), his temperature went to 96.5 to 98 degrees. Then it went down to 93.2 degrees. He covered up with blankets and his temperature increased and the chills stopped. He stated that this was hypothermia. He had low temperatures the following day (28Jan2021) as well, his temperature was 93-94 degrees. His temperature was 93.7 degrees. Other times he checked his temperature and it was 96.5 degrees. When his temperature was low the first time, it only lasted for about three hours. The second time it happened he went to bed and covered up. It lasted for an hour or two. He noticed it again two days ago. The patient also stated the arm he received the injection in was tender however progressed to mild to moderately painful when he experienced the chills and low temperatures. The arm tenderness after getting the vaccine was very mild. He noticed it when he rolled over on his arm. He took some Tylenol for it. His son is an internist. He said the hypothermia was medically significant. His son also said hypothermia is equivalent to a fever in the elderly. The patient wanted to know if there have been any reports of hypothermia after the administration of the vaccine. He has concerns about this occurring after the second dose. He is scheduled to receive the second dose on 15Feb2021 or 16Feb2021. The outcome of the event hypothermia was recovered on 30Jan2021 and pain in arm recovered on 27Jan2021. The outcome of the other events was unknown. The events hypothermia, arm pain and injections site tenderness were assessed as related to BNT16B2.; Sender's Comments: The Company cannot completely exclude the possible causality between the reported hypothermia and the administration of the COVID-19 vaccine, BNT162B2, based on the reasonable temporal association and lacking alternative explanations.   The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to RA, IEC, as appropriate.