Chapter 6: Heat and the Body

What Can Happen

On a hot afternoon, a care worker arrives for a home visit to a man in his eighties who lives alone. The curtains are open, the sun is pouring into the living room and the windows are shut. The man is sitting in his usual armchair in a woollen cardigan. He says that he is fine, but he looks pale and sweaty, the glass of water the care worker left in the morning is still full, and he mentions a headache that started at lunchtime. The care worker feels the heat of the room as soon as she walks in, and she knows that this is the moment to act.

Heat illness ranges from mild problems that pass with rest to heatstroke, which is a life-threatening emergency. Older people and many people who receive care are at higher risk, often without realising it themselves. This chapter explains how the body keeps cool, why some people are especially at risk, and how to tell heat cramps and heat exhaustion from heatstroke. It then shows step by step how to help a person with heat exhaustion and how to keep the people you support cool on hot days. Chapter 7 covers first aid for heatstroke in detail, and Chapter 8 covers heat on the road.

How the Body Keeps Cool and Who Is at Risk

The body works best within a narrow range of temperature. When it gets warm, from hot weather, a hot room or physical effort, the body loses heat in two main ways. Blood vessels near the skin widen, so that warm blood can give off heat through the skin, and the skin sweats, so that heat is carried away as the sweat evaporates. Both ways depend on water, and sweat uses up the body's water and salts, which must be replaced by drinking. Both also work less well in some weather. When the air is as hot as the skin, little heat leaves the body, and when the air is very humid, sweat evaporates slowly and cools the body less.

Age changes these systems. Older people often feel less thirst, so they may not drink enough even when the body needs water. They may sweat less, and the heart and blood vessels may respond more slowly to heat. Many older people also feel the cold more than younger people do, so they may keep the windows closed and wear warm clothes on a hot day, as the man at the start of this chapter did. They may not notice that a room has become dangerously hot.

Health conditions add to the risk. Heart disease, kidney disease, diabetes, breathing problems, dementia and conditions that limit movement can all make it harder for the body to cope with heat, or for a person to do something about it. Some medicines also change the way the body handles heat or water. If you are concerned that a person's medicines may affect them in hot weather, ask the person's doctor or pharmacist, or raise it through your workplace, and never change or stop a medicine yourself. Some people also have a limit on how much they may drink, set by their doctor; follow the care plan, and ask whether the plan should change in hot weather.

Many people who receive care also depend on others to stay cool. A person who cannot get up easily cannot move to a cooler room, open a window or fetch a drink. A person with dementia may not understand that the heat is the reason for feeling unwell, and a person who has difficulty speaking may not be able to tell you. A person in bed under heavy covers, or sitting in a wheelchair in the sun, may become overheated without anyone noticing. This is why your attention and daily habits matter so much: you can notice what the person cannot say.

Heat Cramps, Heat Exhaustion and Heatstroke

Heat also builds up over time. One hot afternoon may be manageable, but several hot days in a row, especially when the nights stay warm, give the body no chance to recover, and the risk of heat illness grows day by day. Indoor heat builds up in the same way: a home with thick walls or a room under the roof may stay hot long after the outside air has cooled. This is why the second or third day of a hot spell, and the hours after a warm night, deserve as much care as the hottest afternoon. Watching the weather over several days, not only today, helps you to plan ahead.

Heat cramps are painful muscle spasms, often in the legs, arms or stomach, that come during or after effort in the heat. They are a sign that the body has lost water and salts through sweat. Help the person to stop, rest in a cool place, sip water and gently stretch the tight muscle. Heat cramps usually ease with rest, and the person should not go back to hard effort in the heat for some time afterwards. Treat them as an early warning: if the person also feels weak, dizzy or sick, think of heat exhaustion.

Heat exhaustion happens when the body has lost too much water and salts and is struggling to stay cool. Common signs are heavy sweating, pale, cool and clammy skin, tiredness and weakness, dizziness or fainting, headache, feeling sick or vomiting, thirst, muscle cramps and a fast pulse. The body temperature may be raised. The key point is that the person's mind stays clear: the person knows where they are and answers you sensibly. Heat exhaustion usually gets better quickly with the right care, but without it, it can turn into heatstroke.

Heatstroke happens when the body's cooling fails and the body temperature rises to a dangerous level, usually about 40 °C (104 °F) or higher. The most important sign is a change in the way the person thinks or behaves: confusion, strange or aggressive behaviour, slurred speech, agitation, drowsiness, a seizure or collapse. The skin is usually hot, and it may be dry or still sweaty, so sweating does not rule out heatstroke. The person may also have a fast pulse, fast breathing, a headache and vomiting. Heatstroke is a life-threatening emergency: call the emergency number at once and start cooling the person, as Chapter 7 describes.

You do not need a thermometer to decide what to do. If a person who has been in the heat shows any change in behaviour or consciousness, treat it as heatstroke and call the emergency number, without waiting to measure the temperature. In older people the signs can be quiet. A person who is unusually sleepy, more confused than usual or unsteady, or who falls, may be developing heatstroke, even indoors and even without having been active. Because you know the people you support, you are often the first to notice that something is different, so trust what you notice and act on it.

Step by Step: Helping a Person With Heat Exhaustion

Step 1. Stop whatever the person is doing and move the person to a cool place: an air-conditioned room if there is one, or the coolest, shadiest room or spot available. Move slowly and support the person, because dizziness can lead to a fall. Outside, find shade first, as Chapter 8 explains for outings and the road.

Step 2. Help the person to lie down, or to sit in a comfortable position if lying down is difficult. If the person feels faint, lying down is safer than sitting, because it prevents a fall. Stay with the person and explain calmly what you are doing. If you are in the person's home, ask someone else who is present to fetch water and cloths, so that you do not have to leave the person alone.

Step 3. Remove extra clothing, such as a cardigan, jacket, hat or heavy blanket, and loosen anything tight around the neck and waist. Respect the person's dignity: ask for consent, and keep the person covered with a light sheet if they wish.

Step 4. Cool the person's skin. Spray or sponge cool water onto the skin and fan the person, or place cool, wet cloths on the neck, face, arms and legs, and renew them as they warm up. Moving air over damp skin cools the body well, so a fan or air conditioning helps. Cold packs wrapped in a cloth can also be placed at the neck and in the armpits.

Step 5. If the person is fully awake and able to swallow safely, give sips of cool water, or a drink made to replace the salts lost in sweat if one is available. Give small amounts often rather than a large amount at once, and help the person to hold the cup if needed. Follow the care plan for the person's drink texture and any limit on drinks, and if the plan limits drinks, contact the person's doctor or nurse as your workplace's procedure says. Never give a drink to a person who is confused, drowsy or cannot swallow safely.

Step 6. Keep watching the person closely and ask how they feel. A person with heat exhaustion should start to feel better quickly with rest, cooling and drinks. Watch the person's colour, breathing and sweating, and above all how clearly the person thinks and speaks.

Step 7. Call the emergency number at once if the person does not start to feel better quickly, gets worse, vomits and cannot keep drinks down, faints, or shows any sign of heatstroke, such as confusion, strange behaviour, slurred speech or drowsiness. Keep cooling the person while you wait, and follow the operator's instructions and the steps in Chapter 7.

Step 8. When the person feels better, help the person to rest somewhere cool for the rest of the day, and keep offering drinks. Even after a full recovery, heat exhaustion is a sign that the person's surroundings or routine need to change. Tell your supervisor, record what happened, and follow your workplace's procedures for informing the family and the person's doctor.

Step by Step: Keeping a Person Cool on Hot Days

Step 1. In the hot season, check the weather forecast at the start of each day, together with any heat warnings issued by the authorities where you work. On days of strong heat, plan the day around keeping the people you support cool, and share the plan with your team.

Step 2. Check the temperature of the rooms where the person spends time, with a room thermometer if your workplace provides one. Keep rooms cool: close the curtains or blinds on the sunny side during the day, keep the windows closed while the air outside is hotter than the air inside, and open them in the cooler evening and night if it is safe to do so. Use air conditioning where it is available. A fan moves air and helps sweat evaporate, but when the air is very hot, a fan alone may not keep a person cool enough.

Step 3. Offer drinks often, without waiting for the person to ask, because many older people do not feel thirsty. A drink offered at every visit, with every meal and between meals, in a cup that the person can hold easily, works better than a reminder to drink. Foods that contain plenty of water, such as fruit and soup, also help, when the care plan's food texture allows them.

Step 4. Help the person to dress in light, loose clothing made of breathable fabrics such as cotton, and to change to lighter bedding at night. Gently offer to swap a warm cardigan for something cooler, and explain why, since many older people are used to wearing warm layers all year.

Step 5. Plan outings, exercise, bathing and other activities for the cooler times of the day, usually the morning and the evening. Avoid the hottest hours for anything that makes the person warm or tired. A cool shower, a cool footbath or a damp cloth on the skin can be refreshing during the day, as long as the water feels comfortable and the person is safe from slipping.

Step 6. Check on the person more often than usual during hot days, and ask how they feel. Look for early signs of heat illness and of not drinking enough: tiredness, headache, dizziness, a dry mouth, dark urine or fewer trips to the toilet, or a change in mood or behaviour. For people who live alone, follow your workplace's procedures for extra visits or calls during hot weather.

Step 7. Keep the nights cool as well as the days. Before the person goes to bed, check that the bedroom is as cool as you can make it, that the covers are light, and that a drink is within reach if the care plan allows it. In a care home or a day centre with night staff, follow your workplace's procedures for checking people during warm nights, since a person who is hot and restless at night may not call for help.

Step 8. Record and report what you notice. Write down how the person seemed, how much the person drank if your workplace records this, and any concern about the home, such as a room that stays very hot or air conditioning that does not work, so that the team can act on it.

Things to Check

Check which of the people you support are at higher risk in hot weather because of their age, health conditions, mobility or care plan, and agree with your team how to protect each one.

Check whether any person's care plan limits drinks, and ask your supervisor or the person's doctor or nurse whether the limit changes in hot weather.

Check that each place where you work has a room thermometer or another way to check the room temperature, and know which room stays coolest.

Check that curtains or blinds, fans and air conditioning work before the hot season starts, and report anything that is broken.

Check that a drink is within the person's reach at every visit, and that the cup suits the person's hands and the care plan.

Check that you can explain the difference between heat exhaustion and heatstroke in a few words: in heatstroke the person's thinking or behaviour changes, and you call the emergency number at once.

Check that your workplace has a plan for hot days, including extra visits or calls for people who live alone, and that you know your part in it.