Heat

Keep cool

• Avoid spending long periods outdoors during the hottest part of the day (11am to 3pm)
• Stay in the shade whenever possible
• Wear light-coloured, loose-fitting clothes
• Minimise unnecessary heating - turn off central heating, electrical equipment and lights that are not needed
• Keep your home cool by closing curtains or blinds during the day and opening windows when temperatures are cooler in the evening and overnight
• Dampening your skin with a wet cloth or wet towel may help to keep you cool
• Fans should only be used if the temperature is <35^oC and should not be pointed directly at you
• Avoid physical exertion or exercising during the hottest part of the day, exercise in the early morning or late evening instead
• Always take a bottle of water with you when going out, and keep a bottle of water in the car
• Never leave babies, children or pets in a parked car

Stay hydrated

• Drink water regularly throughout the day, even if you do not feel thirsty
• Avoid alcoholic drinks, which can also cause dehydration
• Aim for pale-coloured pee as a sign of good hydration
• Check that older adults are drinking enough fluids
• Parents and carers:
  • Babies and young children can become dehydrated quickly during hot weather.
  • Babies under 6 months should continue to receive breast milk or infant formula as their source of fluids.
  • Babies over 6 months can be offered water alongside their usual milk feeds and meals.
  • Encourage children to drink fluids throughout the day.
  • Eating fruits with high-water content (like watermelons, strawberries and melon) can be helpful, while ice lollies and jelly can be an occasional way of increasing fluid intake during hot weather.
• Oral rehydration sachets may be helpful if you feel symptoms of dehydration – talk to your pharmacist about how best to use them

For information on dehydration in adults: Dehydration in adults

For information on dehydration in babies and children: Dehydration in babies and children

Stay sun safe

• If you have to go outdoors, protect your skin by using shade, wear clothing that covers the skin, a wide brimmed hat, sunglasses and sunscreen of 30+ for adults and 50+ for children.
• For more information: How to be sun smart and protect your skin from the sun and sunbeds

1. Heat cramps

Heat cramps are painful muscular spasms, particularly in the legs, arms or abdomen, especially after physical effort in the heat.

What to do: Rest immediately in a cool place and drink sports / electrolyte drinks. Most people recover within 30 minutes. Seek medical help if they do not.

• Heat exhaustion

Heat exhaustion occurs when the body becomes too hot and loses excessive amounts of water and salt through sweat.

Symptoms may include:

• Headache
• Dizziness or light-headedness
• Excessive sweating
• Muscle cramps
• Nause or vomiting
• Weakness or fatigue

What to do: Move the person to a cool place as soon as possible. Remove unnecessary clothing (e.g. jackets, socks). Give them water or diluted fruit juice to rehydrate. Help them rest and cool down (spray or sponge them with cool water and fan them). Most people improve within 30 minutes. Seek medical help if you are concerned or if symptoms do not improve.

• Heatstroke

Heatstroke is a medical emergency that occurs when the body can no longer regulate its temperature.

Symptoms may include:

• Confusion or unusual behaviour
• Loss of consciousness
• Seizures
• Very high body temperature
• Hot, dry skin
• Being drowsy or difficult to wake
• Little / no pee all day

What to do: Call 999 immediately. Cool the person as quickly as possible – spray or sponge with cold water, place ice packs wrapped in cloths on their neck/armpits/groin.

For information on heat exhaustion and heatstroke in children: Heat exhaustion and heatstroke: symptoms, causes, prevention and treatments

For information on heat exhaustion and heatstroke in children: Heat exhaustion and heatstroke in children: symptoms, causes, prevention and treatments

The effects of heat can be more severe for:

• Older adults
• Infants and young children
• Pregnant women
• People with heart, lung, kidney or other chronic medical conditions
• People with dementia
• People experiencing homelessness
• People who work outdoors to undertake strenuous physical activity
• People living alone
• People living in poorly ventilated accommodation

Check on others

Consider checking on relatives, neighbours and friends who may be more vulnerable to the effects of heat, particularly those who live alone or have underlying health conditions.

Ensure that they have access to cool water and know who to call if they feel unwell.

Babies and young children are more vulnerable to the effects of hot weather and can become dehydrated more quickly than adults. Extra care should be taken during periods of hot weather.

Keep children cool

• Keep babies and young children inside or out of direct sunlight during the hottest part of the day (11am–3pm).
• Dress children in light-coloured, loose-fitting clothing.
• Use shade whenever possible.
• Keep bedrooms and living areas cool by closing curtains or blinds during the day.
• Encourage outdoor play during cooler parts of the day.

Protect children from the sun

• Use appropriate sunscreen (SPF 50+) and reapply regularly.
• Ensure children wear hats and protective clothing when outdoors.
• Babies under 6 months should be kept out of direct sunlight wherever possible.

Keep children hydrated

Encourage children to drink fluids regularly throughout the day, before they start to feel thirsty. Foods with a high-water content, such as watermelon, strawberries and melon, can also help maintain hydration. Ice lollies and jellies may be an occasional way of increasing fluid intake during hot weather.

Babies under 6 months

• Continue to provide breast milk or infant formula as the main source of fluids.
• Breastfed babies may wish to feed more frequently during hot weather – make sure to drink plenty of fluids yourself if you are breastfeeding.

Babies over 6 months

• Offer small amounts of water alongside their usual milk feeds and meals.
• Encourage regular fluid intake throughout the day.

Sleeping in hot weather

• Keep bedrooms cool where possible.
• Use lightweight bedding and clothing.
• Ensure babies sleep in a safe sleeping environment and avoid overheating.
• Use a room thermometer to check that the room your baby sleeps in is between 16°C and 20°C – your baby or child should not sleep in direct sunlight.
• A lukewarm bath or shower before bed can also help your child stay cool.

Never leave a child in a vehicle

Never leave a baby, child or pet alone in a parked vehicle, even for a short period. Temperatures inside vehicles can rise rapidly and become dangerous.

Outdoor play and activities

• Encourage regular breaks for drinks and shade.
• Avoid strenuous physical activity during the hottest part of the day.
• Check playground equipment before use, as surfaces can become very hot and may cause burns.

Know the signs of heat-related illness

Symptoms of heat exhaustion can include:

• Headache
• Dizziness
• Excessive sweating
• Nausea
• Fatigue
• Unusual irritability in young children

Move the child to a cool place, encourage fluids and seek medical advice if symptoms persist or worsen.

Seek urgent medical attention by calling 999 if a child becomes confused, difficult to wake, has a seizure, or loses consciousness.

Older adults can be particularly vulnerable to the effects of hot weather. As we age, our bodies become less able to regulate temperature and respond to heat. Certain medical conditions and medications can also increase the risk of heat-related illness.

If you are over 65, or if you care for an older person, the following tips may be helpful.

Keep your home cool

• Close curtains, blinds or shutters on windows exposed to direct sunlight during the day.
• Open windows when temperatures are cooler, particularly in the evening and overnight.
• Turn off any heating and any electrical appliances you are not using.
• If possible, spend time in the coolest room in your home.

Keep yourself cool

• Stay out of direct sunlight during the hottest part of the day (11am–3pm).
• Wear light-coloured, loose-fitting clothing.
• Wear a hat and sunglasses if outdoors.
• Take cool showers or baths, or use a damp cloth to cool your skin.
• Use electric fans if available, ensuring they are used safely.

Stay hydrated

• Drink fluids (water, diluted squash, low-fat milk) regularly throughout the day, even if you do not feel thirsty. Avoid fruit juice, smoothies and soft drinks which can be high in sugar and dehydrate the body. 
• Eating fruits with high-water content (like watermelons, strawberries and melon) can be helpful, while ice lollies and jelly can be an occasional way of increasing fluid intake during hot weather.
• Avoid alcohol and excessive caffeine, which may contribute to dehydration.
• Aim for pale-coloured urine as a sign of good hydration.

Look after your health

• You may find you are less hungry during hotter weather, but it is important to eat – cool meals like sandwiches or salads are recommended.
• Some medical conditions and medications can increase the risk of dehydration or heat-related illness.
• Continue taking prescribed medications unless advised otherwise by your healthcare provider.
• If you have concerns about how hot weather may affect your health or medications, speak with your GP, pharmacist or healthcare provider.
• Keep any medicines according to the storage instructions on the packaging.

Stay connected

• Keep in contact with family, friends or neighbours during periods of hot weather.
• Ask someone to check on you regularly if you live alone.
• If possible, arrange shopping and other activities during cooler parts of the day.

Know the signs of heat-related illness

Heat exhaustion

Symptoms may include:

• Headache
• Dizziness
• Excessive sweating
• Nausea
• Muscle cramps
• Weakness or fatigue

Move to a cool place, drink fluids and rest.

Heatstroke

Heatstroke is a medical emergency.

Symptoms may include:

• Confusion
• Loss of consciousness
• Seizures
• Hot, dry skin
• Very high body temperature
• Drowsiness or difficult to rouse
• Not passing urine all day

Seek urgent medical attention by contacting your GP or calling 999 if heatstroke is suspected.

Periods of hot weather can increase the risk of illness, particularly among vulnerable individuals receiving healthcare or residential care services. Heat stress, heat exhaustion and heatstroke are potentially serious health risks for people during a heatwave and deaths have occurred at home, in residential care facilities and in hospitals.

Healthcare and residential care facilities should have plans in place to minimise the health impacts of hot weather on patients, residents, visitors and staff.

Key messages

• Identify those most vulnerable to heat-related illness.
• Monitor indoor temperature and maintain cooler areas where possible.
• Ensure adequate hydration.
• Recognise the signs and symptoms of heat exhaustion and heatstroke.
• Review preparedness arrangements before periods of hot weather.

Identify those most at risk

Consider those who may be particularly vulnerable, including:

• Older adults (>65 years old)
• Infants and young children
• Pregnant women
• Those who live on their own, and who may not be able to care for themselves, or are socially isolated
• Those living in a residential care facility
• People with cardiovascular, respiratory, renal or neurological conditions
• People with behavioural limitations, such as people with cognitive impairment (dementia/Alzheimer’s), restricted mobility, or those with drug and/or alcohol addictions
• People taking medications that may increase susceptibility to heat-related illness e.g. those that affect heart or kidney function, their ability to sweat, or their cognition or behaviour
• Individuals who are unable to independently regulate their environment or fluid intake
• Patients fasting for procedures or other reasons
• Patients with vomiting/diarrhoea/poor oral intake or other conditions that increase the risk of dehydration

Ensure vulnerable patients and residents are identified and monitored appropriately during periods of hot weather.

Planning and preparedness

Facilities should have arrangements in place before periods of hot weather occur.

Actions may include:

• Monitoring Met Éireann forecasts and weather warnings.
• Identifying patients and residents at increased risk from heat.
• Reviewing local hot weather response plans.
• Ensuring staff are aware of procedures for managing heat-related illnesses.
• Communicating relevant advice to patients, residents, families and carers.
• Reviewing business continuity arrangements for prolonged periods of hot weather.

Managing indoor temperatures

Maintaining a cool indoor environment is an important measure for protecting vulnerable individuals.

Facilities should:

• Draw up a plan for measuring and monitoring indoor temperatures throughout the day and night, particularly in areas occupied by vulnerable patients or residents. Room temperature should be about 20^o
• Identify cooler areas (<20^oC) that can be used during periods of high temperature.
• Prioritise vulnerable patients and residents for cooler areas where feasible.
• Reduce direct sunlight by using blinds, curtains or shading.
• Ensure adequate ventilation.
• Turn off unnecessary lights and electrical equipment where possible.
• Create natural ventilation in clinical areas by opening windows and doors in so far as practical and consistent with comfort and security of patients and staff; the goal is gentle air circulation rather than strong air currents
• Although fans are not recommended in clinical areas, there are certain circumstances where fans may need to be used for patient/resident comfort. If they are to be used there should be a cleaning schedule in place, not pointing in the direction of a patient/resident, and serviced frequently.
• Good ventilation in a room should be the priority. A risk assessment approach be taken in whatever circumstance is deemed necessary by the facility.
• Keep windows closed when air conditioning in use.
• Consider alternatives to plastic pads and mattresses which can make a person warmer.
• Consider whether any areas are prone to overheating and implement measures to reduce temperatures.

Support hydration

Dehydration is one of the most common health risks during hot weather.

Facilities should:

• Encourage regular fluid intake among patients and residents.
• Ensure drinking water is readily available and easily accessible.
• Diluted squash or lower fat milks are also good choices for hydration. Fruit juice, smoothies and soft drinks can be high in sugar which dehydrates the body.
• Monitor individuals who may be unable to request fluids independently.
• Consider additional hydration rounds during periods of hot weather.
• Ensure adequate supplies of drinking water and ice are available.
• Monitor patients at increased risk of dehydration.

Clinical considerations

Healthcare professionals should remain alert to:

• Dehydration
• Heat exhaustion
• Heatstroke
• Exacerbations of cardiovascular and respiratory disease
• Acute kidney injury
• Medication-related complications associated with dehydration

Particular care may be required for patients taking medications that effect fluid balance, thermoregulation or cardiovascular function.

Recognising heat-related illness

Staff should be familiar with the signs and symptoms of heat exhaustion and heatstroke and follow local clinical pathways for assessment and management.

Heat exhaustion symptoms may include:

• Headache
• Dizziness
• Excessive sweating
• Muscle cramps
• Nausea
• Weakness or fatigue

Move the person to a cool environment, encourage fluids (water, and/or sports/rehydration drinks) and monitor closely.

Heatstroke is a medical emergency and requires urgent treatment.

Symptoms may include:

• Confusion or altered mental state
• Drowsiness
• Loss of consciousness
• Seizures
• Hot, dry skin
• Very high body temperature
• Little / No urine output
• Hyperventilation, hypotension and shock

Heatstroke must be manged as a medical emergency. Treatment includes cooling as quickly as possible – spray with cold water, place ice packs on neck/armpits/groin. Do not give aspirin or paracetamol.

Medications

Certain medications have increased risks during hot weather and need to be monitored more carefully.

• Diuretics (especially loop diuretics): can lead to dehydration and electrolyte abnormalities
• Medications that interfere with cardiovascular responses such as antihypertensivesand antianginal drugs
• Medications that interfere with sweating, such as anticholinergicsor beta blockers
• Drugs that cause diarrhoea or vomiting, such as colchicine, antibioticsand opiates, which can lead to dehydration
• Medications that can impair renal function, such as certain antimicrobials, immunosuppressants, non-steroidal anti-inflammatories (NSAIDS), anti-ulcer agentsand chemotherapies
• Agents with levels affected by dehydration, such as lithium, digoxin, antiepileptics
• Drugs that alter states of alertness, such as hypnotics, anxiolyticsand analgesics
• Medications that can interfere with central nervous system thermoregulation, such as neurolepticsand serotoninergic agonists
• Drugs that increase basal metabolic rate such as thyroxine

Storage of medicines
Most medicines should be stored below 25°C and in a cool, dry place. Keep medicines out of direct sunlight, and do not leave on windowsills. Medicines should only be stored in the fridge where specified. Contact your pharmacist for further guidance.

Care delivery considerations

Facilities may wish to consider:

• Rescheduling physiotherapy, exercise programmes and other physical activities to cooler times of day.
• Reducing strenuous activities during peak temperatures.
• Monitoring vulnerable patients more frequently.
• Reviewing staff arrangements during prolonged periods of hot weather.
• Ensuring sufficient staffing capacity to respond to increased care needs.

Staff welfare

Employers should take reasonable measures to reduce heat exposure among staff.

• Ensure access to drinking water.
• Encourage regular breaks.
• Provide access to cooler rest areas.

eople who work outdoors, such as those working in construction, agriculture, landscaping, utilities, etc., may be at increased risk during periods of hot weather.

Outdoor workers are exposed to heat, direct sunlight and ultraviolet (UV) radiation, which can increase the risk of dehydration, heat exhaustion, and heatstroke and skin cancer. Outdoor workers may receive 2-3 times more UV radiation exposure than indoor workers.  

Advice for Outdoor Workers

Stay hydrate

• Drink water regularly throughout the day, even if you do not feel thirsty
• Increase fluid intake during hot weather and when undertaking strenuous work
• Avoid excessive caffeine which may also cause dehydration
• Take regular breaks to drink water
• Sports drinks or electrolyte drinks may also be helpful if you have sweated a lot

Stay cool

• Where possible, schedule more physically demanding work for cooler parts of the day (early morning or evening)
• Take regular rest breaks in shaded, cooler areas, especially between 11am and 3 pm
• Be aware that high temperatures can increase fatigue and reduce concentration, potentially increasing the risk of accidents

Protect your skin from the sun

Follow the SunSmart 5Ss:

1. Slip on clothing that covers your skin, such as long sleeves, collared t-shirts.
2. Slop on broad-spectrum sunscreen (UVA and UVB) with SPF 30 or higher on exposed skin. Apply 20 minutes before going outside and re-apply every two hours, particularly if sweating.
3. Slap on a wide-brimmed hat, or a safety helmet fitted with a brim and neck protection where appropriate.
4. Seek shade during breaks and lunch periods, particularly between 11am and 3pm.
5. Slide on wraparound sunglasses that provide UV protection.  

Know the signs of heat-related illness

Early signs of heat exhaustion may include:

• Excessive sweating
• Thirst
• Headache
• Dizziness
• Muscle cramps
• Nausea
• Fatigue

What to do: Move to a cool area, rest and drink fluids if these symptoms develop.

Heatstroke is a medical emergency. Call 999 and seek urgent medical attention if someone becomes confused, loses consciousness, has a seizure, or develops a very high body temperature.

Advice for Employers 

Employers have a responsibility to assess and manage risks associated with working outdoors in hot weather.

Employers should consider:

• Monitoring weather forecasts and planning work accordingly
• Rescheduling physically demanding tasks to cooler times of the day where possible
• Providing easy access to drinking water
• Encouraging regular hydration breaks
• Ensuring workers have access to appropriate protective clothing, hats, and sunscreen
• Providing information on recognising the signs of dehydration, heat exhaustion and heatstroke

Particular care may be needed for workers who:

• Have underlying health conditions
• Are pregnant
• Wear heavy or restrictive PPE
• Undertake strenuous physical work

See HSE SunSmart video link for outdoor workers  or visit www.hse.ie/sunsmart/ for more information.

The most up-to-date weather warnings are available at Met Éireann - The Irish Meteorological Service

• Walk dogs early in the morning or late in the evening when the ground is cooler
• Always ensure your pets have access to fresh water and shade, both indoors and outdoors
• Never leave pets locked in cars or conservatories or other enclosed spaces that heat up quickly