First Aid for Hot Weather: How to Stay Safe During High Temperatures

When temperatures rise, many people look forward to spending more time outdoors. However, hot weather can also present significant health risks. Understanding first aid for hot weather can help you recognise the early signs of heat-related illness, provide appropriate first aid, and prevent a minor problem from becoming a medical emergency.

Heat-related illnesses can affect anyone, but some people are particularly vulnerable. Whether you are enjoying the sunshine, working outdoors, caring for others, or supporting individuals in health and social care settings, knowing how to stay safe in warm weather is an important life skill.

Heat exhaustion can develop quickly in hot weather. Knowing the signs and how to respond could help prevent a medical emergency.

Why Hot Weather Can Be Dangerous

The human body normally regulates its temperature through sweating and increased blood flow to the skin. During periods of high temperatures, these natural cooling mechanisms can become overwhelmed, particularly if a person becomes dehydrated or is exposed to heat for prolonged periods (NHS, 2025).

When the body cannot cool itself effectively, heat-related illnesses can develop. These range from mild heat cramps and heat exhaustion to life-threatening heatstroke (UKHSA, 2024).

Who Is Most at Risk During Hot Weather?

While anyone can develop a heat-related illness, some groups are at greater risk.

People at increased risk include:

• Older adults, particularly those aged 65 and over

• Babies and young children

• Individuals living with dementia

• People with heart disease, respiratory conditions, diabetes, or kidney disease

• Individuals taking medications that may affect hydration or temperature regulation

• People with reduced mobility

• Outdoor workers

• Athletes and those undertaking strenuous exercise

• Individuals who are dehydrated

• People who are overweight or obese

The NHS and UK Health Security Agency advise taking extra precautions to protect vulnerable individuals during periods of hot weather and heat-health alerts (NHS, 2025; UKHSA, 2024).

How to Stay Safe in Warm Weather

The best approach to first aid for hot weather is prevention.

Simple measures include:

• Drink water regularly throughout the day, even before feeling thirsty.

• Avoid excessive alcohol, which can contribute to dehydration.

• Wear lightweight, loose-fitting clothing.

• Use sunscreen and seek shade where possible.

• Avoid strenuous activity during the hottest part of the day, typically between 11am and 3pm.

• Keep homes and workplaces as cool as possible by closing curtains and blinds exposed to direct sunlight.

• Check regularly on vulnerable family members, neighbours, and individuals you support.

• Plan outdoor activities for cooler parts of the day.

The NHS also recommends avoiding prolonged exposure to direct sunlight and increasing fluid intake during periods of hot weather (NHS, 2025a).

Signs and Symptoms of Heat Exhaustion

Heat exhaustion occurs when the body loses excessive water and salt through sweating.

Common signs and symptoms include:

• Heavy sweating

• Cool, pale, clammy skin

• Dizziness or light-headedness

• Headache

• Muscle cramps

• Nausea or vomiting

• Weakness and fatigue

• Increased thirst

• Fast pulse

• Feeling faint

Heat exhaustion is not normally life-threatening if recognised and treated promptly (British Red Cross, 2025).

First Aid for Heat Exhaustion

If you suspect heat exhaustion:

1. Move the person to a cool place, ideally indoors or in the shade.

2. Remove unnecessary clothing, such as jackets, hats, or excess layers.

3. Encourage them to drink cool water, an isotonic sports drink, or an oral rehydration solution if available.

4. Cool their skin using cool water, damp cloths, a spray bottle, or fanning.

5. Apply cold packs wrapped in a cloth to the neck, armpits, or groin if available.

6. Stay with them and monitor their condition.

Most people should begin to cool down and feel better within 30 minutes if treated appropriately (NHS, 2025).

If symptoms do not improve within 30 minutes, contact NHS 111 (or NHS 24 in Scotland by calling 111) for urgent medical advice, as heatstroke may be developing. If the person develops signs or symptoms of heatstroke, call 999 immediately (NHS, 2025; NHS Inform, 2025).

Signs and Symptoms of Heatstroke

Heatstroke is a medical emergency. It occurs when the body's temperature rises to dangerous levels and it can no longer regulate its heat effectively.

Signs and symptoms may include:

• Very high body temperature, often above 40°C

• Hot, flushed skin

• Confusion, agitation, or unusual behaviour

• Slurred speech

• Severe headache

• Rapid breathing

• Rapid pulse

• Dizziness

• Loss of coordination

• Seizures

• Loss of consciousness

Unlike heat exhaustion, a person suffering from heatstroke may stop sweating despite being dangerously overheated (St John Ambulance, 2024).

First Aid for Heatstroke

If heatstroke is suspected:

1. Call 999 immediately.

2. Move the person to a cool environment.

3. Remove excess clothing.

4. Cool the person rapidly using cool water, wet towels, fans, or ice packs placed around the neck, armpits, and groin.

5. Continue cooling until emergency services arrive.

6. If the person becomes unresponsive and is not breathing normally, commence CPR if trained to do so.

Heatstroke can lead to organ failure and death if not treated promptly (Resuscitation Council UK, 2021).

Heat Exhaustion vs Heatstroke

Understanding the difference between heat exhaustion and heatstroke is an important part of providing effective first aid.

Heat Exhaustion	Heatstroke
Heavy sweating	Sweating may stop
Cool, clammy skin	Hot, flushed skin
Headache	Severe headache
Dizziness	Confusion or altered behaviour
Muscle cramps	Seizures may occur
Nausea	Loss of consciousness possible
Usually improves within 30 minutes	Medical emergency requiring 999

HSE Guidance on Working in Hot Weather

Many workplaces become significantly hotter during summer months, particularly outdoor environments and physically demanding work settings.

Although there is no maximum legal workplace temperature in the UK, employers have duties under the Health and Safety at Work etc. Act 1974 to protect workers from risks associated with excessive heat.

The Health and Safety Executive (HSE) advises employers to:

• Carry out suitable and sufficient risk assessments.

• Provide access to drinking water.

• Allow regular rest breaks.

• Improve ventilation where possible.

• Adapt work schedules to avoid the hottest parts of the day.

• Monitor workers for signs of heat stress.

• Consider the impact of personal protective equipment (PPE) on body temperature.

Employers should consult workers and review control measures where excessive heat may affect health, safety, or wellbeing (HSE, 2025).

What Should Be in a First Aid Kit for Hot Weather?

Whether you are attending an outdoor event, working outside, or supporting vulnerable individuals, a hot weather first aid kit can help you respond quickly to common summer health concerns.

Consider including:

• Bottled drinking water

• Oral rehydration sachets

• Instant cold packs

• Sunscreen (SPF 30 or above)

• After-sun lotion

• Burn gel dressings

• Sterile dressings and plasters

• Disposable gloves

• Digital thermometer

• Cooling towels

• Emergency contact information

A well-stocked first aid kit should complement, not replace, preventive measures such as hydration, shade, and appropriate clothing.

When Should You Call 999?

Call 999 immediately if someone:

• Shows signs of heatstroke

• Becomes confused or disoriented

• Has a seizure

• Loses consciousness

• Stops responding normally

• Is not breathing normally

Early recognition and rapid cooling can significantly improve outcomes in heat-related emergencies (British Red Cross, 2025).

Learning Practical First Aid Skills

Understanding first aid for hot weather forms part of wider first aid knowledge. Early recognition and intervention can prevent serious illness and potentially save lives.

At Slanjava Learning Ltd, our accredited First Aid training courses provide learners with the practical knowledge and confidence needed to respond to a wide range of medical emergencies, including heat-related illnesses, environmental injuries, and sudden illness.

Whether you require Emergency First Aid at Work, First Aid at Work, or First Aid at Work Requalification training, we can help your team develop the skills needed to respond effectively when it matters most.

Kind regards,

Slanjava Learning Ltd | Helping others to help others  

Award-winning Health & Social Care Training

-slàinte mhath-

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References and Further Reading

• British Red Cross (2025) Heatstroke symptoms and first aid. Available at: https://www.redcross.org.uk/first-aid/learn-first-aid/heatstroke (Accessed: 24 June 2026).

• Health and Safety Executive (HSE) (2025) Temperature, thermal comfort and heat in the workplace. Available at: https://www.hse.gov.uk/temperature (Accessed: 24 June 2026).

• NHS (2025) Heat exhaustion and heatstroke. Available at: https://www.nhs.uk/conditions/heat-exhaustion-heatstroke/(Accessed: 24 June 2026).

• NHS (2025a) Heatwave: how to cope in hot weather. Available at: https://www.nhs.uk/live-well/seasonal-health/heatwave-how-to-cope-in-hot-weather/ (Accessed: 24 June 2026).

• NHS Inform (2025) Heatstroke and heat illness. Available at: https://www.nhsinform.scot/illnesses-and-conditions/a-z/heatstroke-and-heat-illness/ (Accessed: 24 June 2026).

• Resuscitation Council UK (2021) First Aid Manual. 11th Edition. London: Dorling Kindersley.

• St John Ambulance (2024) Heat exhaustion and heatstroke. Available at: https://www.sja.org.uk/get-advice/first-aid-advice/heat-exhaustion-and-heatstroke/ (Accessed: 24 June 2026).

• UK Health Security Agency (UKHSA) (2024) Beat the Heat: Staying Safe in Hot Weather. Available at: https://www.gov.uk/government/publications/beat-the-heat-hot-weather-advice (Accessed: 24 June 2026).

• World Health Organization (WHO) (2025) Tips for keeping cool during hot weather. Available at: https://www.who.int/initiatives/initiative-against-extreme-heat-and-health-risks-in-workplaces-and-major-events/tips-for-keeping-cool (Accessed: 24 June 2026).

Disclaimer

The information contained in this article is provided for general educational and informational purposes only and reflects guidance available at the time of publication.

While every effort has been made to ensure accuracy, this article should not be considered a substitute for professional medical advice, diagnosis, treatment, workplace risk assessment, or formal first aid training.

If someone is seriously unwell, injured, experiencing a medical emergency, or showing signs of heatstroke, seek appropriate medical assistance immediately by calling 999.

Readers should always follow current organisational policies, procedures, professional guidance, and applicable legislation relevant to their role and location. Slanjava Learning Ltd accepts no liability for any loss, injury, or damage arising from reliance on the information contained within this article.

Article Information

Title: First Aid for Hot Weather: How to Stay Safe During High Temperatures

Organisation: Slanjava Learning Ltd | Helping others to help others

Author: Lee Johnston

First Published: June 2026

Last Reviewed: June 2026

Next Review Due: June 2027 or sooner if there are significant changes to first aid guidance, public health advice, workplace health and safety requirements, heat-health alerts, or guidance issued by the NHS, UK Health Security Agency (UKHSA), or Health and Safety Executive (HSE).