With the arrival of the first signs of summertime, our thoughts often turn to swimming, barbecues and balmy, carefree holidays, but those who are ill or have chronic disease must also fit their medicines into that picture.

One complication is intense heat saps medications’ effectiveness and can ruin them. Everyday medical devices, such as asthma inhalers, could even explode when the thermometer rises too high.

Another summer challenge that interferes with good care: Many types of drugs undermine our ability to withstand hot weather and are linked to heat stress, heat stroke and related hospitalizations.

Your medications are precious cargo. Cedars-Sinai Chief Pharmacy Officer Rita Shane, PharmD, advises keeping a close eye on all prescription and over-the-counter drugs you take to ensure their integrity. Start with checking their labels, which should explain specific storage recommendations, as well as risks. Pharmacists recommend keeping most pills in their original containers and storing them somewhere cool, dry and not exposed to the elements. This will also protect them from light, which can cause some medications to deteriorate.

"Awareness of safe storage is crucial," Shane said.

Avoid storage in enclosed spaces such as your car trunk or glove compartment— common mistakes that can disable epinephrine (EpiPens) and other emergency treatments. In the heat, indoor car temperatures can soar well beyond outside levels.

For home deliveries, experts recommend tracking your order, particularly when extreme weather is in the forecast. Ideally, the package should be left outside for no longer than an hour.

Cedars-Sinai Pharmacy Initiatives Manager Sarah Stephens, PharmD, suggests discussing precautions with your mail-order company.

Medicines and supplements may not be shipped in packaging resistant to extreme weather conditions for prolonged periods.

"It’s up to the consumer" to be aware and prevent weather damage in those cases, Stephens cautioned.

When it’s time for summer travel, pharmacists advise keeping your medications with you, not in your checked luggage, which could get lost or wind up somewhere hot.

In addition, refrigeration (36 to 46 degrees) is needed with certain medications such as adalimumab and dupilumab, insulin, weight-loss drugs (semaglutide) and often antibiotics. If you are flying, Cedars-Sinai pharmacists recommend:

• Carrying medicine in an insulated cooler with an ice, cold or gel pack. Add extra ice, if needed, but make sure it is well-wrapped so it doesn’t come into contact with the drug.
• Clearly labeling all containers with your name.
• On long journeys, advising a flight attendant, who can assist with refrigerating or replenishing ice and cooling packs.

Even if you leave your cherry-red tablets out in the heat, they might look normal. It can be difficult to determine whether medications have been spoiled.

"You can’t rely solely on visual cues," Stephens said.

Speak to your pharmacist before deciding what to do with questionable medication. The impact of extreme temperatures might be surprising. For example, heat could amplify a drug’s potency, speeding up its release and raising the risk of an overdose.

Pharmacists point to a host of medicines that can make you more vulnerable to the sun, possibly leading to dehydration or heat stroke:

• Over-the-counter pain relievers (aspirin, acetaminophen)
• Mental health treatments (antipsychotics, antidepressants, stimulants)
• Nervous system drugs (anticholinergics, seizure medications)
• Diuretics (water pills)
• Many cardiovascular medications (beta blockers, ACE inhibitors)

They can block your body’s natural methods of regulating internal temperature by retaining sweating, blood flow and thirst.

These whole-body impacts raise the likelihood of dehydration, fainting and falls, according to the Centers for Disease Control and Prevention. If you get dehydrated, a drug can build up in your system, posing further risks such as heat stroke and kidney damage.

"Especially as people age, hydration is important," Shane emphasized.

Along with drinking plenty of water on warm days, watch for dizziness, exhaustion, feeling faint and either increased or reduced sweating. Any of those could signal a reaction. 

Some of these common treatments—even antacids and laxatives—also disturb the stability of electrolyte nutrients, which leads to similar symptoms. Electrolyte imbalance, in turn, can trigger serious cardiac complications.

It could be tempting to skip doses, or easy to forget about medications, when you’re having fun. Abruptly stopping a medication, though, can be dangerous.

Instead, talk with your doctor or pharmacist, or both, about possible medication changes before the extremely hot weather arrives. In some cases, older or high-risk patients on multiple drugs may be able, temporarily, to exceed fluid restrictions or take lower doses of drugs.

It’s crucial, however, to keep medication safety in mind during the summer.

"Patients are on so many important medications, whether for their heart, high blood pressure, an infection or cancer,” Shane said. “We shouldn’t let weather get in the way."