Is it common for children to sweat a lot whilst sleeping whether its during the day or night. My 4yr old had her tonsils and adeniods removed a wk ago?

Yes. Yes it is more common for kids to sweat at night. They should be dressed for comfort with care not to overbundle. However if they HAV not had sweating at night previously and it is a new problem, it should be evaluated.
Sweating. The perception of excessive sweating at night is fairly common. We all sweat at night as it is part of normal rem sleep.Excessive sweating may be related to an underlying medical condition and you should talk to your doctor. Temperature of the room, blankets and pajamas also can contribute to excessive sweating so pay attention to that also.