Unable to get through military exercises after receiving the Pfizer Covid Vaccine; some possible increase in heat exhaustion; this was kind of like a heat stroke; This is a spontaneous report received from a contactable reporter(s) (Physician) from medical information team for a Pfizer sponsored program (159558).  A 22 year-old male patient received bnt162b2 (BNT162B2), administration date 03Jun2021 10:18 (Lot number: EW0180) at the age of 22 years as dose 2, single for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Bnt162b2 (First dose: 12May2021, lot: EW0175, Time administered: 0955 , Route of administration: alternating deltoid), administration date: 12May2021, for COVID-19 immunization. The following information was reported: HEAT EXHAUSTION (non-serious) with onset 2021, outcome "unknown", described as "some possible increase in heat exhaustion"; HEAT STROKE (non-serious) with onset 2021, outcome "unknown", described as "this was kind of like a heat stroke"; GENERAL PHYSICAL HEALTH DETERIORATION (non-serious) with onset 11Jun2021, outcome "recovered" (12Jun2021), described as "Unable to get through military exercises after receiving the Pfizer Covid Vaccine". The events "some possible increase in heat exhaustion", "this was kind of like a heat stroke" and "unable to get through military exercises after receiving the pfizer covid vaccine" were evaluated at the emergency room visit. Relevant laboratory tests and procedures are available in the appropriate section.  Additional information: Report 3 of 4. Report 3 is regarding patient number 3, 22 year old male. MI filed on report 1. Reporter was a military physician and had reported some of his men (referring to military people) were actually experiencing some difficulty in carrying out there usual military exercises as compared to before. He mentioned some possible increase in heat exhaustion but he was not positive that it was caused by the vaccine.some of the caller's men were unable to get through military exercises after they received the Pfizer Covid Vaccine.  This event happened to many of the men after receiving the Pfizer Covid Vaccine. Unable to get through the military exercises after receiving the Pfizer Covid Vaccine: The reporter reports this was kind of like a heat stroke. The reporter wants to know if any precautions need to taken for X amount of days after receiving the Pfizer Covid Vaccine? Causality: The reporter states the event was probably heat and humidity related issue, peoples conditioning. The reporter was the officer assigned to investigate the situation.  The reporter wants to make sure he is not missing anything. The caller would like to know any recommendations, the reporter states he has not seen taking it easy for longer than a week or two after receiving the Pfizer Covid Vaccine.  The reporter states he was not completely done with the whole interview process right now. The reporter reports 28 people have had heat casualties after receiving the Pfizer Covid Vaccine. Right now the reporter had 5 peoples information.  Causality: The reporter states the event is not a direct correlation, more of an indirect kind of thing that just popped up.  Whether the event is a thing or more of like, a bunch of other reasons the caller can think of that this could happen including heat and humidity. Prior Vaccinations (within 4 weeks) list any other vaccinations within four weeks prior to the first administration date of the suspect vaccine(s): The reporter can confirm no vaccines of any kind were given with 14 days of the Pfizer Covid Vaccines.  Follow-up attempts are completed. No further information is expected.; Sender's Comments: Linked Report(s) : US-PFIZER INC-2021755866 Same reporter/ drug/ AE, different patient