I’m so sorry about your chicken! It’s so hard to lose a pet
It’s very possible that she passed from heat stress. 108 is pretty hot… is this much higher than it’s been lately where you live? It could be that her body couldn’t handle the sudden shock of a drastic temperature change.
Did you notice if she was acting strange or differently than normal in any way? Was she panting, lethargic, closing eyes, drooping wings, not eating, etc? Have you seen her injured or possibly hurt in any way recently? How has her poo looked? Watery, bloody, very dark or black, etc?
Even if it wasn’t from the heat, here are some tips to keep your other chickens cool during the hot summer months…
-feed cool fruits as treats (watermelon, berries, peaches, apples, etc)
-increase coop ventilation; still air is often worse than warm air
-discontinue feeding or do not feed scratch grains; they actually warm the bird from the inside as it digests these seeds and grains
-provide a shallow pool (such as a kiddie pool) with a few inches of water that the chickens can step and walk in; the feet are one of the main body parts which release body heat.
-provide 2-liter soda bottles or gallon-size milk jugs of ice for the chickens to lay against and keep cool
-make sure that they have plenty of shade and water all the time.
I hope some of this helps, and again, I’m so, so sorry about your hen.