Question:

When light rain began to fall the players of one team left the green to take shelter in the clubhouse without seeking the consent of their opponents who wanted to continue playing. What should be done?

Answer:

No player should delay play by leaving the rink of play or their team unless their opponent agrees, and then only for no more than 10 minutes. If a player or team breaks this law, they will forfeit the game to their opponents. Laws 33.1 & 33.8
 

Question:

During a singles match, one player leaves the green to change some clothing. Is this permitted?

Answer:

A player can only leave the green with the consent of the opponent and then only because of illness or other reasonable cause. The absence may not exceed 10 minutes. Law 33.1