Personal protective equipment and heat: risk of heat stress

Summary

This week temperatures are set to be very high. The UK Health Security Agency (UKHSA) has issued a Red Heat Health Alert (HHA) for:

• the West Midlands
• the East Midlands
• the South East
• the South West
• London
• the East of England

These 6 regions will be under a red heat-health alert from 1am on Wednesday 24 June until 11pm on Thursday 25 June.

In addition, an amber alert has been issued for the North West, North East, and Yorkshire and the Humber for the same period.

A red extreme heat warning has also been issued by the Met Office National Severe Weather Warning Service.  

Wearing personal protective equipment (PPE) in warm or hot environments increases the risk of heat stress. This occurs when the body is unable to cool itself enough to maintain a healthy temperature. Heat stress can cause heat exhaustion and lead to heat stroke if the person is unable to cool down.

Measures should be put in place to control the temperature in clinical and care environments. Staff should also be supported to adapt their behaviour to stay cool and well hydrated. Staff may require more frequent breaks and the frequency of PPE changes are likely to increase, with a resulting increase in demand.

Actions for employers and managers

Assess the risk of overheating in your workplace and consider implementation of appropriate control measures.

Consider environmental control measures first (for example, remove or reduce the sources of heat and improve ventilation, where possible).

Consult the Adverse Weather and Health Plan for England.

If you don’t already receive UKHSA/Met Office heat-health alerts, sign up for these so that you are up to date on latest alert levels for your area.

Ensure that all staff are aware of the risk of heat stress when wearing PPE and know how to reduce their risk.

Satisfy yourself that there is a cascade in place to ensure that frontline staff receive the alerts and information they need to stay safe.

Ensure that PPE supplies are sufficient to cover a likely increase in demand for certain PPE items during hot weather due to staff changing equipment more frequently.

Consider whether more staff may be needed per shift to maintain service levels while accommodating increased staff breaks.

Consider whether some staff are more vulnerable to the effects of heat and manage this appropriately .

Any actions taken must be aligned with local infection prevention and control policies and national guidance. See:

• Temperature in the workplace: Managing workplace temperatures (HSE)
• National infection prevention and control manual (NIPCM) for England (NHS)

Actions for staff

Staff working in warm or hot conditions should:

• take regular breaks, find somewhere cool if you can
• make sure you are hydrated (checking your urine is an easy way of keeping an eye on your hydration levels – dark or strong-smelling urine is a sign that you should drink more fluids)
• be aware of the signs and symptoms of heat stress and dehydration (thirst, dry mouth, dark or strong-smelling urine, urinating infrequently or in small amounts, inability to concentrate, muscle cramps, fainting) – don’t wait until you start to feel unwell before you take a break
• consider using a buddy system with your team to look out for the signs of heat stress (such as confusion, looking pale or clammy, fast breathing) in each other
• between shifts, try to stay cool as this will give your body a chance to recover

Background

Hospitals and other care settings in England are at risk of overheating in warm weather. During summer 2022, 50.2% of trusts reported having at least one incident of overheating, and 5% of trusts reported over 50 incidents (1).

Occupational heat strain is associated with productivity loss and has an impact on the health of those affected (2).

Employers have a responsibility to ensure a reasonable working temperature in workrooms and local heating or cooling where a comfortable temperature cannot be maintained (3). Adequate ventilation can impact the risk of heat stress for those working in warm or hot conditions. Ventilation should inform your assessment of the risk and selection of measures to control the potential for heat stress.

Health and care staff, including ambulance staff, may be required to wear PPE for infection prevention and control purposes. The PPE required is specified for different settings and activities in line with national guidance. This can effectively require them to wear PPE for the entirety of their clinical work.

Wearing PPE in warm or hot environments increases the risk of heat stress because:

• PPE reduces the body’s ability to evaporate sweat and prevents heat loss through convection and radiation (4)
• scope for staff to adapt to their environment by removing clothing may be compromised through the necessary wearing of PPE
• the impact of PPE on a person’s risk of heat stress in a health or social care setting will depend on work rate, workplace climate, PPE and the individual

Heat stress can present as heat exhaustion and lead to heat stroke if the person is unable to cool down. Heat exhaustion is when someone becomes very hot and starts to lose water or salt from their body. Heat stroke is where the body is no longer able to cool itself and a person’s body temperature becomes dangerously high.

The signs of heat exhaustion include:

• headache
• dizziness and confusion
• loss of appetite and feeling sick
• excessive sweating
• becoming pale
• clammy skin
• cramps in the arms, legs and stomach
• fast breathing or pulse
• temperature of 38°C or above
• being very thirsty

If someone is showing signs of heat exhaustion, they need to be cooled down. More information about heat exhaustion, heat stroke and actions to take to cool down is available on the NHS website.

Demand on PPE equipment may increase as PPE may need to be changed more often due to increased regularity of breaks (during which PPE must be discarded). PPE also needs to be changed and discarded when it becomes uncomfortable or damp, for example with sweat.

Health and social care workers will need to take more frequent breaks to cool down which may impact on productivity.

For queries relating to PPE and workplace risk assessments, that cannot be answered from information available on the HSE website, or by the local health and safety risk management team, please contact HSE using their online working safely enquiries form at Ask about health and safety

For queries relating to the Heatwave plan and heat-health alerts, please contact ExtremeEvents@ukhsa.gov.uk

References

1. NHS England. ‘Estates Returns Information Collection, Summary page and dataset for ERIC 2022/23 - NHS England Digital’

2. Flouris AD and others. ‘Workers’’ health and productivity under occupational heat strain: a systematic review and meta-analysis’

3. Health and Safety Executive. ‘Managing workplace temperature Temperature in the workplace: Managing workplace temperatures - HSE’ (viewed on 23 June 2026)

4. Potter AW and others. ‘Ebola Response: Modelling the Risk of Heat Stress from Personal Protective Clothing’ PLoS One 2015: volume 10, issue 11, article e0143461