He experienced cramping up from the 2nd COVID-19 Vaccine shot, and he was cramping up with his last 2 nights of sleep/cramping happened during the night, and was mainly in his feet; he had a little bit of sweating after his second COVID-19 Vaccine; This is a spontaneous report received from a contactable consumer (patient). A 72-years-old male patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE), dose 2 via an unspecified route of administration, administered in arm right on 19Apr2021 10:30 (Lot Number: EW0153) as single dose for covid-19 immunisation. Medical history included Hydration deficiency, drop foot in his left leg that was caused by a back surgery. The patient's concomitant medications were not reported. The patient previously took bnt162b2 (Lot Number: EP7534) in arm right on 29Mar2021 for Covid-19 immunization. No additional vaccines administered on same date of the bnt162b2. No other prior vaccinations (within 4 weeks).  The patient experienced cramping up from the 2nd COVID-19 vaccine shot. He said he knew his cramping up was from dehydration because he had a dehydration problem in his background. He said though it was mentioned, he wanted to stress how important drinking water was with the COVID-19 vaccine. He said he had a little bit of sweating after his second COVID-19 vaccine, and it was no biggy. He said he was cramping up with his last 2 nights of sleep. He clarified the cramping happened during the night, and was mainly in his feet. He said he was not miserable, but knew the cramping was from dehydration. Cramps did not last a long duration. He said he wanted to suggest that Pfizer tell the COVID-19 Vaccine shot providers to stress more hydration. He said people should forgo any other liquid consumption. He clarified people should stay away from soda, alcohol, and coffee, and stick with drinking water for 2-3 days after getting the COVID-19 Vaccine. He said he was trying to stress hydrating more when people get the second COVID-19 vaccine shot. The patient reported his hydration deficiency was partially due to his past working environment. He said he was in the aluminum industry, and was exposed to a lot of hot temperatures for years. He said the aluminum mill had been shut down for 20 years, and he was exposed to the hot temperatures 25 years before that. No further details provided. The cramps were probably due to his hydration deficiency from the past, and his hydration deficiency just happened to coincide with his second COVID-19 vaccine shot. The patient reported the cramping was mainly in his feet, and only at night. He said he had used a cane for the 12 past years due to drop foot in his left leg that was caused by a back surgery. He said he did not know whether his drop foot was an extenuating circumstance, or not, to the cramping he experienced. The cramping occurred for the past 2 nights, and he did not know if he was going to have cramping again tonight. The patient just drank some water as treatment. The events did not require a visit to emergency room or physician office. Events occurred on 19Apr2021. Outcome of cramping was not recovered, of sweating was recovered.  No follow-up attempts are needed. No further information is expected