“Does dim posibl dileu’r risg yn llwyr fyth ond rydyn ni’n cynghori’r rhai sy’n gwarchod eu hunain i ymarfer ar amseroedd llai prysur, fel bod y risg o gyswllt ag eraill yn is.
“Risk can never be completely eliminated but we advise those shielding to exercise at times that are less busy, so the risk of contact with others is reduced.