ST JOHN Ambulance, the volunteer-led health charity, has teamed up with the Gazette to bring you some simple summer first aid tips.

This week, Basingsotke unit manager Joshua Hensman, takes us through what to do when someone is dehydrated.

Dehydration occurs when someone loses fluid from the body and does not replace it. If untreated, someone with dehydration can develop heat exhaustion.

Possible causes

• Excess sweating during exercise

• Too much exposure to the sun or humid conditions

• Sweating from a raised body temperature. For example, a fever

• Loss of fluid from severe diarrhoea and vomiting.

What to look for

• A headache or light-headedness  

• Dizziness or confusion

• A dry mouth and dry eyes  

• Dry or cracked lips

• Reduced amounts of dark urine  

• Muscle cramps, such as to the calves

• Special attention should be paid to babies and young children as they may also have pale skin with sunken eyes and can deteriorate very quickly.

What to do 

1. Reassure the casualty and help them to sit down

2. Give them plenty of water. Oral rehydration solutions can help to replace fluid as well as salt and other minerals they’ve lost

3. If they have any painful cramps, encourage them to rest. Help them to stretch and massage the muscles that are affected 

4. Monitor the casualty’s level of response. If the casualty appears to be unwell, seek medical advice.

For more free first aid advice go to St John Ambulance’s website at or download the free first aid app from your app store.

For information about volunteering with St John Ambulance in Basingstoke, contact Joshua Hensman on