Guard cells and the stomata?

good old plant physiology problem. First when plants are in the heat the stomata/ guard cells close due to loss of water. it is like when we get hot we want to rehydrate our selves because we respire water. Same thing with plants they respire too, but in a different way. they hold in water so they won't respire water because the plant will die due to dehydration. they can't get water from the sink. lol and also another factor is water loss through the soil. when a plant looses water through the soil on a hot day the stomatas also close. for the next question, house plants are mostly tropical plants. the reason why they are thicker is because of the mesophyll cells and for photosynthesis. plants that are in light for most of the day, like outdoor plants, they tend to have thinner leaves because of the light intensity. just think of a forest. the trees that are tall get more light then others. so they don't need so much mesophyll cells for photosynthesis. plants that are on the ground need a broader, greener, and thicker leaves due to the lack of sun light.