You’ve been looking forward to a pool day all summer. But after baking in the sun for a while, every little thing gets on your nerves. This day was supposed to be relaxing, but you can’t help but feel agitated. Why is that?

Jason Schofield, a primary care physician assistant (PA), says the heat may be to blame.

How heat affects us

We all know how it feels to be overheated–from feeling thirsty to having headaches or nausea. But some lesser-known symptoms are just as common and can actually affect your emotions.

When your body gets too hot, its stress response is activated, releasing higher levels of stress hormones, such as cortisol and adrenaline. This can lead to emotional changes like increased agitation, impatience, heightened anxiety, and, in the most extreme cases, mental fogginess and confusion.

Even though these symptoms may seem unrelated to the heat, it’s best not to overlook them.  “Symptoms can be different for everybody,” Scholfield says. “But it’s our body’s way of indicating that something is wrong.”

If you continue to overheat, you could experience heat exhaustion, which can lead to heat stroke. This occurs when the body can no longer control its temperature, and blood flow to the brain is disrupted.

“If somebody starts to become confused or agitated,” Schofield says, “it might be an early sign that they’re getting ready to have a heat stroke or they’re getting some heat exhaustion.”

Heat stroke is the most severe kind of heat illness and is considered a life-threatening emergency. If you or someone you know is experiencing heat stroke, go to the emergency room as soon as possible.

Beating the heat

Although avoiding the heat entirely is difficult, Schofield says to limit your exposure on particularly hot days. Also, be sure to check on your loved ones and make sure they are keeping cool.

To avoid overheating, Schofield recommends the following:

• Wear loose clothing with breathable fabric.
• Keep your fan or air conditioning on.
• Take breaks when outside.
• Exercise indoors.
• Stay hydrated.

He also says to keep in mind what medications you are taking. Some can cause faster dehydration and make you more affected by extreme heat conditions.

When to speak to your doctor

If you cannot stay hydrated by drinking water, or if symptoms like headaches and mental distress continue, talk to your doctor about potentially underlying conditions.