The situation occurred during one of our mixed matches. At the beginning of the second set and after winning the first, the opposing male player started to cramp and needed time to rest. After about 4 minutes our guys were wondering if he should forfeit, but none of the players knew the rules. Luckily, play resumed soon after and was completed.
The following is from the league coordinator:
Cramping does get a medical time-out – however it’s only one.
I think 5 minutes is reasonable – and then they have to continue playing. If they cramp again (even if it’s in a different area of the body) they have to continue play or retire.
Bill found the following on old ITF rule book..
30. CONTINUOUS PLAY & REST PERIODS
b. Play shall never be suspended, delayed or interfered with for the purpose of enabling a player to recover his strength, breath, or physical condition. However, in the case of a treatable medical condition, the Umpire may allow a one-time three minute time-out for that medical condition.