The lake doesn’t get warmer while you stand there dipping your toe. Jump in and adjust.

Standing at the edge testing the temperature gives you information you already have, and repeating it only extends the cold part. Adjustment happens after entry, not before, which means the deliberation is not preparation, it is delay. The dread is doing all the work and none of the swimming.

When you catch yourself checking the same thing for the fourth time, go. Count to three and move on the three. The adjustment takes about a minute, and it cannot start until you are in.