Why are seedlings planted in a cool place?

When growing seedlings (after the seeds have sprouted), care must be taken that the air temperature is not too high. A cool atmosphere will keep the sprouts from over-stretching and make them stronger and hardened.

And when planting seedlings in open ground, again, heat should be avoided, because delicate sprouts can get sunburn or even die. Better to engage in planting seedlings in cloudy weather, or at least in the evening when the heat subsides.