Why Heat Is a Problem for Medicines
Insulin
Adrenaline Auto-Injectors
Thyroid Medicines
GTN Tablets & Sprays
The Contraceptive Pill
Certain Antibiotics
Seniors and Children Are Most at Risk
For Seniors
- Often on multiple regular medicines (blood pressure, diuretics, heart) several of which affect the body's ability to regulate temperature.
- Reduced thirst sensation and mobility can mean medicines get left in bags, cars or conservatories without anyone noticing.
- Caring for an elderly relative? Check where medicines are kept during a heatwave, especially insulin, GTN spray or injectables.
For Children
- Liquid medicines (antibiotics, paracetamol suspension, inhalers) are often left in school bags or cars during summer outings, the conditions that degrade them fastest.
- Asthma inhalers are especially heat-sensitive, keep them out of direct sunlight, hot cars and away from radiators, as heat can affect the dose delivered.
- If a child's medicine has been exposed to high heat, don't assume it's still working, even if it looks and smells the same.
Planning for Warmer Climates
Pack medicines in hand luggage, not the hold. Aircraft holds reach extreme temperatures and aren’t climate-controlled like the cabin, especially important for insulin and auto-injectors.
Ask for a summary of what you’re taking and why, particularly for Egypt or destinations where you may need to explain medicines at customs or seek local medical help.
Build in a buffer, pack a few extra days’ supply for delays, and split medicines between hand luggage and a companion’s bag where practical, in case one goes missing.
Heading Somewhere Hot?
Everyday Situations That Put Medicines at Risk
Pharmacy Bag in the Car
Postal Deliveries
Handbags & Rucksacks
Windowsills
How to Protect Your Medicines This Summer
Your Summer Storage Checklist
- Never leave medicines in the car, even for a "quick errand", take them inside with you.
- Bring in deliveries promptly, don't let prescriptions sit on the doorstep in the heat.
- Ask about storage instructions for any new prescription, some need refrigeration, others have heat sensitivities you may not know about.
- Use a cool bag or insulated pouch with an ice pack for insulin, injectables or other heat-sensitive medicines when travelling.
- Store in a cool, dry place away from windows and radiators, not the bathroom, as humidity is also a factor.
Your Questions, Answered
Can I take my inhaler through airport security?
Yes. Inhalers are allowed in hand luggage and don’t count towards your liquids allowance. Carry it in its original packaging and keep it with you rather than in the hold, since cabin temperatures are far more stable.
Can I take insulin on a plane?
Yes, insulin and other injectable medicines are permitted in hand luggage, and this is actually the recommended way to carry them rather than checking them in. Airlines may ask for a letter from your GP or pharmacist confirming you need to carry it, so it’s worth requesting one before you travel.
How do I know if my medicine has been affected by heat?
Unfortunately, you often can’t tell just by looking, smelling or tasting it. If a medicine has been left somewhere hot, a car, a hotel room without air conditioning, direct sun, the safest approach is to bring it in and ask your pharmacist rather than assume it’s still fully effective.
Does the contraceptive pill stop working in heat?
Extreme heat exposure can affect the pill’s effectiveness over time, though a short period in a bag on a hot day is unlikely to cause an issue. If it’s been left somewhere very hot for an extended period, such as a car during a heatwave, it’s worth checking with your pharmacist.
What's the best way to keep insulin cool while travelling?
Can I get extra medicine before travelling in case of delays?
In many cases, yes, speak to us in advance and we can talk through options for an extra supply, particularly for regular repeat prescriptions, so you’re not caught short if your return journey is delayed. NHS rules on early supply can be strict, so it’s worth checking against your repeat prescription policy in good time.
