How Summer Heat Can Affect Your Medications — And What You Should Know

As temperatures rise during the summer months, most people remember to stay hydrated and avoid spending too much time in the sun. But what many people don’t realize is that hot weather can also affect how certain medications work in the body — and even how they should be stored.

At John’s Pharmacy, we want our community to stay healthy and safe all summer long. Here’s what you should know about the connection between heat, hydration, and your medications.

Why Summer Heat Matters

Extreme heat can put added stress on the body. When temperatures climb, your body works harder to stay cool by sweating and increasing circulation. For some individuals — especially older adults, children, and people with chronic health conditions — this can increase the risk of dehydration, dizziness, heat exhaustion, and even heat stroke.

Certain medications may also make it harder for your body to regulate temperature or retain fluids properly.

Medications That May Increase Heat Sensitivity

Some common medications can affect how your body responds to heat, including:

• Blood pressure medications
• Diuretics (“water pills”)
• Antihistamines
• Certain antidepressants
• Diabetes medications
• Stimulants
• Some heart medications

These medications may increase sweating, reduce sweating, affect hydration levels, or make you feel dizzy or lightheaded in hot conditions.

If you take one or more of these medications, it’s important to be extra cautious during periods of high heat.

Signs You May Be Dehydrated

Dehydration can happen quickly during the summer — especially if you’re spending time outdoors or exercising.

Watch for symptoms such as:

• Dry mouth
• Fatigue
• Headaches
• Dizziness
• Muscle cramps
• Dark-colored urine
• Increased thirst

If you experience severe dizziness, confusion, fainting, or rapid heartbeat, seek medical attention right away.

Don’t Leave Medications in the Car

Heat can also damage medications themselves.

Many prescriptions and over-the-counter products should be stored at room temperature. Leaving medications in a hot car, direct sunlight, or outside for extended periods can reduce their effectiveness.

This is especially important for:

• Insulin
• Inhalers
• EpiPens
• Liquid medications
• Certain antibiotics

Always check storage instructions on your medication label, and contact your pharmacist if you’re unsure whether a medication may have been exposed to excessive heat.

Summer Safety Tips for Medication Users

To help stay safe this summer:

• Stay Hydrated — Drink water consistently throughout the day — even if you don’t feel thirsty.
• Avoid Peak Heat Hours — Try to stay indoors or in shaded areas during the hottest part of the day, usually between 10 a.m. and 4 p.m.
• Dress for the Weather — Wear lightweight, breathable clothing and use sunscreen when outdoors.
• Monitor Symptoms Carefully — Pay attention to how you feel, especially if starting a new medication.
• Ask Your Pharmacist Questions — Your pharmacist can help you understand whether your medications may increase heat sensitivity and provide guidance for safe summer use.

We’re Here to Help

At John’s Pharmacy, your health and safety are our top priorities year-round. If you have questions about your medications, hydration, or summer health concerns, stop by or give us a call. Our team is always happy to help you stay informed and protected this season.

Stay safe, stay cool, and enjoy your summer!

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Medically Reviewed By
Abe Funk, PharmD | Katrina Hillier, PharmD | Derek Palisch, PharmD