As the mercury outside rises, you may notice your mood start to fall.
It's called summer-onset seasonal affective disorder. As the temperature heats up, people often close their windows and blinds to stay cool.
But not getting enough light can actually cause you to lose your desire to do things and become lethargic or agitated.
"Being less attentive, organized, less engaged with other people," Dr. Norman Rosenthal, a clinical professor of psychiatry at Georgetown University School of Medicine, said.
"Then maybe even feeling somewhat down or sad. But the energy is often the first thing you'll notice."
Dr. Rosenthal recommends lowering your AC, taking a cold shower, or getting at least 35-40 minutes of sunlight every morning.
If the problem continues, he recommends seeing a doctor.