Heat related hazards

Hot weather can affect anyone, but some people are more vulnerable to the effects of heat than others. During periods of hot weather or heatwaves, the risk of dehydration, heat exhaustion and heatstroke increases. Older adults, infants and young children, people with chronic medical conditions and those who work outdoors may be particularly affected.

In Ireland, a heatwave is generally defined as a period of five or more consecutive days with a maximum temperature over 25^oC.

Protect yourself during hot weather

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

Heat-related illnesses

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.

2. 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

3. 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

Who is most at risk?

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.

Caring for pets in hot weather

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

Additional HPSC resources

Heat Health Advice for Older Adults - Health Protection Surveillance Centre

Heat Health Advice for those with children - Health Protection Surveillance Centre

Heat Health Advice for Health and Care Professionals - Health Protection Surveillance Centre

Bathing Water - Health Protection Surveillance Centre

Wildfires - Health Protection Surveillance Centre

Additional resources

For the latest weather updates and heat warnings: Met Éireann - The Irish Meteorological Service

For Child Safety advice in hot weather: Sun and outdoor safety for children

For Child Safety around water: Water safety for babies and children

For Water Safety: WATER SAFETY

For Sun Safety advice: How to be sun smart and protect your skin from the sun and sunbeds