Plant leaves and young, tender plants can become scorched, wilted in direct sunlight. In such conditions compost can rapidly dry out making the small seedlings vulnerable to collapse. Many greenhouse plants during the growing season would require some form of shading protection in the greenhouse from strong/direct sun light.
Product solution: Paint those panel most exposed to sun with Coolglass Greenhouse Shading.
Cultural methods: Water plants in the morning and/or evening, and avoid watering in direct sunlight or when the temperature in the greenhouse/conservatory is very high.