So sleepy, so tired

I wonder if it's because the weather's gotten cooler? (but it's still super hot at noon Lately, for some reason, I'm just super sleepy and super tired My eyes just won't stay open I really wanted to just lie down and sleep on my way to work this morning No matter if I drink ginseng powder/coffee/tea/energy drinks, or listen to music, it doesn't seem to help I hope I can recover soon, I feel like my brain isn't working properly in this state