The fourth umpire (sometimes referred to as the reserve umpire), is a cricket umpire. For all international matches a fourth umpire is required to perform duties like bringing on the new ball, carrying drinks on to the field for the umpires, checking the batteries in the light meter, observing the pitch during the lunch and tea intervals to make sure there is no interference, or bringing on new bails. The fourth umpire will take over the third umpire duties if something happens to one of the on-field umpires, as the rules state the third umpire will take over on-field duties.