Advice and resources Staying well in hot weather

Overview

Hot weather can cause heat exhaustion and heatstroke, which can quickly become a medical emergency.

You are more likely to become ill during hot weather if you:

  • are over 65 years old
  • are 5 years old or younger
  • have a long-term health condition
  • need help to look after yourself
  • have a learning disability, dementia, mental health problems, or a drug or alcohol addiction

It can also be harder to keep cool if you’re in a building that is well-insulated against cold weather, in a city, or covered windows which don't open wide. 

Being in a room on a higher floor or facing the sun will also make it harder to keep cool.

Heatstroke

Heatstroke happens when your body can't cool down, and your core temperature get higher than 40ºC despite resting in a cool place and drinking fluids for 30 minutes or longer.

Symptoms

  • a very high temperature
  • hot skin that is not sweating and might look red, which can be harder to see on darker skin shades
  • a fast heartbeat
  • fast breathing or shortness of breath
  • confusion and lack of coordination
  • a seizure or fit
  • loss of consciousness

If you suspect someone has heatstroke, call 999.

While you wait for assistance, put them in the recovery position if they have lost consciousness, and continue efforts to cool them down.

You can prevent heatstroke by keeping cool and hydrated and watching for signs of heat exhaustion.

Heat exhaustion

Heat exhaustion happens when you have lost too much water.

Common symptoms include:

  • tiredness
  • weakness
  • feeling faint
  • headache
  • muscle cramps
  • feeling or being sick
  • heavy sweating and intense thirst
  • a core temperature between 38ºC and 40ºC

Try to cool yourself or the person down as quickly as you can. Heat exhaustion does not usually need emergency medical attention if the person cools down within 30 minutes.

Heat exhaustion can lead to heatstroke.

If a person is cooling down and feeling better within 30 minutes, this suggests they are improving.

If this does not happen or you're concerned about symptoms, contact NHS 111.

In an emergency, or if you think someone has heatstroke, call 999.

How to keep cool in hot weather

Keep yourself cool

  • move to a cooler place, like a a room with air conditioning or somewhere in the shade which should ideally be cooler than 26°C
  • Avoid physical activity during the hottest time of the day and reschedule activities like physiotherapy to cooler times of the day
  • Take regular cool showers, baths, or body washes
  • Wear light, loose-fitting clothes that absorb sweat and prevent skin irritation
  • Minimise sun exposure between the hours of 11am and 3pm
  • Use sunscreen
  • Sprinkle clothes with water regularly and splash cool water on your face and the backs of your neck
  • remove thick clothing, like jackets or socks
  • Eat cold food, particularly salads, fruit, and ice-lollies that have a high-water content
  • Drink water or fruit juice on a regular basis and avoid alcohol
  • Monitor body weight to track fluid intake - a kilogram change in weight roughly equals a litre of fluid gained or lost
  • use cold packs wrapped in a cloth and put under the armpits or on the neck

Keep your home cool

  • cool the room down with a fan, or open windows and doors to left a draft flow
  • use curtains, blinds or shutters on your windows
  • open windows in the morning and evening
  • turn your heating off and use air conditioning if you have it
  • check that your fridge and freezer are working properly
  • turn off any appliances that you don’t need
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Medications that increase risk during hot weather

Some medications can increase the risk of becoming ill during hot weather. The level of risk depends on your lifestyle and health status, as well as your medications.

Some examples of medications include:

  • diuretics, especially loop diuretics, which can lead to dehydration and electrolyte abnormalities
  • medications which interfere with cardiovascular responses, such as antihypertensives and antianginal drugs
  • medications that interfere with sweating, such as anticholinergics or beta blockers
  • medications that cause diarrhoea or vomiting, such as colchicine, antibiotics, and opiates
  • medications that can decrease renal function, such as certain antimicrobials, immunosuppressants, non-steroidal anti-inflammatories, anti-ulcer agents, and chemotherapies
  • drugs with levels affected by dehydration, such as lithium, digoxin, and antiepileptics
  • drugs that alter states of alertness, such as hypnotics, anxiolytics, and analgesics
  • medications that can interfere with central nervous system thermoregulation, such as neuroleptics and serotonin receptor agonists
  • drugs that increase the basal metabolic rate, such as thyroxin

Storing medications during a heatwave

Most medicines should be kept below 25°C, so they should be stored somewhere cool, dry, out of direct sunlight, and away from windowsills.

Medicines should only be stored in the fridge if specified.

Learn more about why temperature management is important for medicines storage from the Specialist Pharmacy Service (SPS).

Resources

NHS UK

Find more information about the impact of hot weather on health and staying safe in the sun.