What happens if a junior batter isn't wearing a helmet?

Under the ECB Recreational Cricket Safety Regulations, every batter under 18 must wear a helmet with a faceguard or grille when batting against a hard ball (and a box if male). Parental consent to bat without one is not accepted.

Appointed Umpire, batter has not started their innings

1. The bowler's end umpire stops the game, tells the batter and their captain (team manager in junior cricket) that a helmet is required, and sends the batter off to return wearing one.
2. If the batter refuses, once 3 minutes have passed they are out, Timed out (Law 40.1) and play continues with the next batter.

Appointed Umpire, batter has started their innings and takes the helmet off

1. Stop the game and tell the batter and captain that a helmet must be worn.
2. If they refuse: treat it as batter time wasting. Warn both batters (first and final warning) and tell the other umpire and both captains.
3. If they still refuse: award 5 penalty runs to the fielding side (Law 41.10).
4. If they still refuse: the batting side is refusing to play and the match is awarded to the fielding side (Law 16.3.1.2).

Acting Umpire (not appointed): stop the game; the batter must put on a helmet or be replaced by a batter who has not already batted and is wearing one. Do not restart until this happens. If play doesn't resume within 15 minutes, the batting team forfeits the match.