The plants can take the "radiant" heat that comes from the light if the "ambient" temperature is low enough so that when the fan that you have on the plants blows across them, it cools them to the level of the ambient temperature.
The "ambient" means the temperature of the air itself. "Radiant" heat is the energy that is held within the photons of light coming from a light source. When those photons strike a surface or pass through a resistance, they will release some of their energy as heat. The plants have a unique ability to absorb some of that energy so that it doesn't release as heat. That ability is photosynthesis. However, some of the energy from the photons isn't able to be absorbed so it does get transformed into heat. Some of that heat radiates back into the air and some stays within the leaves. The plant responds to the buildup off heat the same way we do, by sweating. Its not called sweating in plants, it is called transpiration, but it still a release of water which carries away some of the heat from within the plant.
If there is a good enough breeze blowing across the plant, both the re-radiated heat and the transpiration will be carried away on the breeze. However, if the ambient temperature of the space gets too high, the plants struggle to release that inner heat and will begin to shut down certain functions.
Now when you measure the temperature of a space, you are measuring the ambient temperature (or the level of heat energy that is in the air) This is done through direct contact of the heat energy in the air with the temp measuring device). But if your thermometer is in direct light, it is getting the contact energy from the air AND it is getting radiant energy from the photons of light that is hitting it and releasing the energy within those photons as heat. At this point you art not accurately measuring the "ambient" temperature, which is what we use to determine the level of functionality for the plants.
I hope all this makes sense for you.
