Storing Medicines in a Hot Climate: A Practical Guide

What this article covers

Why does heat damage medicines?
Insulin and heat: the highest-stakes medicine for people with diabetes
Liquid antibiotics: they need a fridge, every time
Asthma inhalers and respiratory medicines in the heat
Power cuts: a backup plan for refrigerated medicines
Travelling with medicines in the heat
Where should you store medicines at home?
How do you know if a medicine has been damaged by heat?
Medicines that need the closest attention in the Arab region

Why does heat damage medicines?

Medicines are precisely engineered chemicals, and most are manufactured and tested within a defined temperature range, usually 15 to 25 degrees Celsius. When the temperature exceeds that range, chemical reactions inside the product accelerate: the active ingredient breaks down or changes structure, reducing its effectiveness or, in some cases, producing harmful breakdown products.

A study published in the European Journal of Clinical Pharmacology in 2003 found that many common drug formulations had not been adequately tested for stability under tropical and hot-climate conditions, meaning that the storage instructions printed on the packaging may not reflect the real thermal reality of the Middle East and North Africa.

Summer temperatures across the Arab world, from Iraq to Egypt to the Gulf, regularly reach 35 to 50 degrees Celsius in the shade. Inside a closed room without air conditioning, or inside a parked car, temperatures can exceed 60 degrees within minutes. In that context, correct medicine storage is a direct patient-safety issue.

Storage requirements for common medicines

Medicine	Required temperature	Key note
Insulin, unopened	2 to 8 degrees C (fridge)	Never freeze
Insulin, in-use pen	Below 25 to 30 degrees C	Discard after 28 to 30 days
Liquid antibiotics, reconstituted	2 to 8 degrees C	Expires in 7 to 14 days
Asthma inhalers (bronchodilators)	Below 25 degrees C	Keep from direct sunlight and heat
Paracetamol tablets	Below 25 degrees C	Keep in original packaging
Suppositories	2 to 8 degrees C or below 25 C	Melt quickly in summer heat
Eye drops	Below 25 degrees C	Close tightly after each use

Insulin and heat: the highest-stakes medicine for people with diabetes

Insulin is the most heat-sensitive common medicine and the most dangerous when damaged, because a person with diabetes cannot simply take a smaller dose to compensate. A 2021 study published in PLoS ONE tested several insulin types under tropical temperature conditions and found that insulin loses significant biological activity when repeatedly exposed to elevated temperatures, even when it still looks visually normal.

The practical rule: unopened insulin must be kept in a refrigerator at 2 to 8 degrees Celsius, away from the freezer wall and away from the fridge door. Freezing destroys it just as heat does. An opened pen or vial can be carried at a normal room temperature for up to 28 to 30 days, but never leave it in a car or on a shelf in direct sunlight.

Signs of damaged insulin to look for: discolouration or cloudiness in types that should be clear, clumping in cloudy types such as NPH, or thread-like particles visible through the glass. If you notice any of these, replace the pen or vial and do not use it. Tell your pharmacist or doctor.

Researchers writing in Tropical Doctor in 2002 documented insulin storage in clay pots kept damp with water as a practical cooling method in areas without refrigeration. Today, insulated cool bags and frozen gel packs are more accessible alternatives, but the underlying principle remains the same: insulin needs active, continuous cooling, not just shade.

Liquid antibiotics: they need a fridge, every time

A 2020 systematic review published in the European Journal of Hospital Pharmacy found that many liquid antibiotics, including amoxicillin and amoxicillin-clavulanate, lose a significant proportion of their active concentration when stored above recommended temperatures, even for short periods.

When you collect a reconstituted liquid antibiotic from the pharmacy, ask the pharmacist directly whether it needs refrigeration. The answer differs by antibiotic type and matters enormously. As soon as you get home, place it in the fridge at 2 to 8 degrees Celsius. Do not leave it on a kitchen shelf even for a single day during summer.

Tablets and capsules are generally more stable than liquid forms, but they too need to be kept away from humidity and heat. The bathroom medicine cabinet is one of the most popular and one of the worst storage spots because temperature and humidity fluctuate with every shower.

Asthma inhalers and respiratory medicines in the heat

Pressurised inhalers contain a propellant gas under pressure, and exposure to high heat raises the internal pressure, which can damage the canister or cause the medicine to be released in an uncontrolled burst. The practical limit is never leaving them anywhere that could exceed 50 degrees Celsius.

A car parked in summer sun can reach 70 degrees or more inside within minutes. The rescue inhaler you keep in the car for a child must travel with the child or in a carried bag, not sit in the boot of the car for weeks at a time.

Before travelling or at the start of summer, check the dose counter on your inhaler to make sure it is giving accurate readings. If you use a daily preventive corticosteroid inhaler, do not stop it in summer because you feel well. Stopping suddenly without medical advice is risky.

Power cuts: a backup plan for refrigerated medicines

Frequent power cuts are a reality in Syria, Lebanon, Iraq, and parts of Egypt. A closed fridge typically maintains its internal temperature for up to four hours if the door stays shut. If you or a family member depends on insulin, biological medicines, or vaccines stored at home, a backup plan is not optional, it is part of managing the condition.

Practical steps: a portable insulated cool bag with frozen gel packs provides several hours of protection. Keep a supply of gel packs in the freezer at all times. If a power cut extends beyond eight hours, contact your pharmacy or the nearest hospital to store critical medicines temporarily.

Do not use insulin that has been outside refrigeration for more than two hours in temperatures above 35 degrees. The apparent saving from one vial is not worth destabilising your diabetes management. If you are unsure after a long power cut, speak to your pharmacist and replace it.

What to do during a prolonged power cut

1Keep the fridge door closed: it holds its temperature for about four hours
2Place frozen gel packs beside refrigerated medicines inside the fridge
3Transfer heat-sensitive medicines to an insulated cool bag after four hours
4Contact your pharmacy or nearest hospital if the power cut passes eight hours
5Note how long the medicine was outside normal temperature and tell your doctor before using it

Travelling with medicines in the heat

Road travel in summer through the desert, or in a car where the air conditioning is switched off during stops, exposes medicines to repeated cycles of heat and cooling. It is not only a single high-temperature event that harms a medicine; repeated thermal cycling also degrades stability.

When travelling by air, carry heat-sensitive medicines in your hand luggage rather than in checked baggage. The hold of an aircraft can get extremely cold and damage medicines that need refrigeration but not freezing. Insulin and biological medicines travel in the cabin without difficulty, typically with a letter from your doctor.

Medicines that need special attention when travelling include suppositories and creams that liquefy in heat, eye drops, and blood glucose test strips. Test strips are damaged by heat and humidity and give false readings, something many patients do not know. Keep them in their original sealed container, away from heat and moisture.

Where should you store medicines at home?

The two most popular home storage spots, the bathroom cabinet and the kitchen shelf, are also among the worst choices. The bathroom is humid and its temperature swings with every shower. The kitchen generates heat from cooking. A dry drawer or cupboard in the living room or bedroom, away from windows and heat-generating appliances, is a much better choice.

The World Health Organization's guidance on good storage and distribution practices for medical products specifies that optimal conditions include controlled temperature, humidity and light, and that direct light exposure damages many medicines, particularly solutions and liquids. Keep medicines in their original, often opaque, packaging.

A practical additional rule: do not store medicines permanently in your car. Many people keep emergency medicines in the glove box and forget them there for months. In an Arab summer, a parked car turns into an oven that can render those medicines useless or unsafe.

How do you know if a medicine has been damaged by heat?

The real difficulty is that a heat-damaged medicine does not always show obvious signs. A tablet labelled 'store in a cool place' that was exposed to 50 degrees for several hours may look completely normal to the eye, while its active ingredient has degraded significantly.

Signs you may be able to see: colour change in tablets or liquids, an unusual smell, a change in texture or consistency, tablets with coatings that have softened or stuck together. But the absence of these signs does not guarantee the medicine is safe.

The practical rule: if you know that a sensitive medicine was stored outside its recommended temperature range, do not risk using it. The apparent saving is not worth the clinical consequence. Speak to your pharmacist and get a replacement. For ongoing medicines like insulin or thyroid treatment, a brief gap with medical guidance is far safer than using a compromised product.

Medicines that need the closest attention in the Arab region

Because of the intense heat and the difficulty of reaching healthcare facilities consistently in some areas, certain medicines deserve a higher level of attention. Insulin and associated testing supplies for people with diabetes are at the top of the list, given how rapidly heat can damage them and how serious the consequences of using a degraded product are. Equally critical are biological medicines (Biologics) used for autoimmune conditions, rheumatology and oncology, as these protein-based therapies are among the most temperature-sensitive products on the market.

Levothyroxine, taken daily by people with underactive thyroid, is another medicine where stability matters greatly. Even modest variation in effective dose, caused by a degraded tablet, can cause noticeable symptoms because the thyroid controls so many body systems. Store these tablets in their sealed packaging in a cool, dry place, and if you notice unexpected changes in how you feel, mention to your doctor that the tablets may have been exposed to heat.

Vaccines stored at home in areas with limited access to health centres are a particular concern. Vaccines are destroyed by both heat and freezing, and can become completely ineffective without any visible change in appearance. This is known as a cold chain break. If you live in an area with frequent power cuts and you are storing vaccines at home, speak with a health worker about the safest approach before assuming refrigeration alone is sufficient.

The Sihtak app lets you log each medicine in your household alongside its storage instructions, and set reminders to review your stock before summer begins. The app is a practical tool for staying organised, but decisions about whether a medicine is still safe to use always belong to your pharmacist or doctor.

Frequently asked questions

Can I store unopened insulin in the freezer to save fridge space?

No. Freezing destroys insulin just as extreme heat does. Unopened insulin must be kept in the fridge at 2 to 8 degrees Celsius, away from the freezer compartment and away from the fridge door where temperatures vary. An in-use pen or vial can be kept at a moderate room temperature for up to 30 days, but never frozen.

I left my medicine in the car for two hours in summer. Is it still safe?

It depends on the medicine and the actual temperature inside the car. In a hot summer, a parked car can reach 60 to 70 degrees internally, enough to damage many medicines. For sensitive medicines like insulin or reconstituted liquid antibiotics, replace anything that was left in those conditions and speak to your pharmacist.

What is the best place to store children's medicines at home?

A dry drawer or cupboard away from direct light, heat and moisture, and well out of reach of children. Avoid the bathroom and the kitchen. Liquid medicines for children that require refrigeration must go in the fridge immediately after opening, and should be discarded at the expiry date marked on the bottle after reconstitution.

Can I take insulin on a long-haul flight?

Yes. Carry insulin in your hand luggage, not in checked baggage, because the aircraft hold can freeze it. Use an insulated cool bag with gel packs. Most airlines allow insulin and needles in the cabin with a letter from your doctor. Ask your pharmacist about adjusting timing if you are crossing time zones.

Do blood pressure and heart medicines also degrade in heat?

Some do, particularly liquid forms or those with specific storage instructions. Dry tablets in original packaging stored in a cool, dry place are generally more stable. Read the storage instructions on every box, and ask your pharmacist if you are unsure, especially for medicines you take every day where consistency of effect matters.

The power cut lasted all night and I do not know if my insulin is still safe. What should I do?

If the fridge stayed closed throughout and the outage was under four hours, insulin is usually still safe. If it was longer, or if you notice any change in the insulin's appearance, do not take the risk of using it. Contact your pharmacist or the nearest health facility and explain what happened so they can advise you and arrange a replacement if needed.

Do blood glucose test strips get damaged by heat?

Yes. Test strips are sensitive to both heat and humidity and can give false readings if they have been damaged. Keep them in their original sealed container, store them in a cool dry place, and never leave them in a car or near a window. If your blood sugar readings seem unexpectedly high or low, consider whether the strips may be the cause before adjusting your treatment.

Sources

This content is for health education only and is not a substitute for medical advice. If you have symptoms that worry you, see your doctor.