particular threshold of that index — particular threshold of that index for introducing certain restrictions or interruptions to play— restrictions or interruptions to play so what we did for these _ to play so what we did for these sports, for example the australian open, we develop something called the australian open _ something called the australian open heat stress scale which rates — open heat stress scale which rates the _ open heat stress scale which rates the heat stress risk on a scale — rates the heat stress risk on a scale of— rates the heat stress risk on a scale of i- _ rates the heat stress risk on a scale of 1— five and then as the — scale of 1— five and then as the risk— scale of 1— five and then as the risk escalates as it gets progressively hotter, or more humid, — progressively hotter, or more humid, we increased the threshold number and then that would _ threshold number and then that would then advise players to adopt— would then advise players to adopt certain strategies that nright— adopt certain strategies that might be quite — that have been demonstrated in scientific settings to mitigate the heat stress — settings to mitigate the heat stress risk of those plays, particularly in a tennis —related setting, as we go from two to— —related setting, as we go from two to three, is where we recommend that players start implementing certain calling strategies that have been demonstrated in scientific studies _ demonstrated in scientific studies to be effective and reducing the rise in core temperature of tennis players, when _ temperature of tennis players, when we — temperature of tennis players, when we reach four the advice is then— when we reach four the advice is then interruption to play with—