Typically seasonal affective disorder is associated with the darker evenings and cooler temperatures of the winter; but summer can bring about the same symptoms of depression for some people.

Extreme heat "impacts very basic comfort levels," especially once temperatures exceed 85 degrees Fahrenheit, says Smriti Joshi, licensed clinical psychologist and chief psychologist at Wysa, a mental health app.

It doesn't help that we're seeing higher temperatures than normal due to climate change, she adds. "There's a lot of feeling of helplessness and loss of control because [of] weather changes and climate change that's been happening globally that can trigger a lot of anxiety," Joshi tells CNBC Make It.

Here are some symptoms of summertime (SAD)ness that you should be aware of, she says.

6 signs you're experiencing summertime seasonal affective disorder

• Increased stress
• Sleep disturbances, including insomnia
• Feelings of fatigue
• Irritability
• More frustration than usual
• Inability to concentrate and focus

"Heat can lead to heat stroke and dehydration which can also have an impact on mental health," says Joshi. "That can also lead to a lot of stress and anxiety."

When the weather rises in the summer, "more instances of road rage happen," she adds. Collectively, people resort to unhealthy coping mechanisms like substance use, drinking more alcohol and either over-eating unhealthy foods, including ice cream, or not eating enough, says Joshi.

Certain groups that are more at-risk of heat stroke in extreme heat, like pregnant people and older individuals, are also more likely to stay inside on really hot days, and this can cause them to feel lonelier, she notes.

10 ways to combat SAD in the summer

These are a few recommendations from Joshi for fighting off the symptoms of SAD that can affect you during the summer:

1. Stay hydrated
2. Avoid excessive exposure to heat if you can
3. Take small breaks if you work outdoors
4. Use fans or A.C. to cool off
5. Connect with loved ones virtually
6. Avoid consuming alarming climate news too often, especially misinformation
7. Engage in emotionally-relaxing hobbies that aren't physically draining
8. Take pauses inside your home. Over exertion even in your air-conditioned home can make you feel hotter.
9. Eat nutritious meals
10. Get in touch with a mental health professional if you notice concerning changes in your mental health

"At this point in time, there can be an increase in both physical health and mental health incidences," says Joshi. "The simple things which people often forget can be really helpful."

Correction: This story was updated to reflect that extreme heat "impacts very basic comfort levels" once temperatures exceed 85 degrees Fahrenheit. A previous version misttated the temperature.

DON'T MISS: Want to be smarter and more successful with your money, work & life? Sign up for our new newsletter!

Take your business to the next level: Register for CNBC's free Small Business Playbook virtual event on August 2 at 1 p.m. ET to learn from premier experts and entrepreneurs how you can beat inflation, hire top talent and get access to capital.

• 6 steps to protect yourself from extreme temperatures, says author of ‘The Heat Will Kill You First’
• 8 tips for staying positive during SAD season, from a psychiatrist