How the Body Reacts to Extreme Heat
As the outside temperature rises the body begins to have to work a great deal harder to keep its internal temperature regulated. The normal human body temperature is 37C and all of our internal systems operate at around this temperature efficiently. When the body gets hot than is normal it reacts in several ways to cool down.
The first reaction that occurs is the capillaries that are close to the surface of the skin widen to promote movement of heat from the body’s center to its extremities, and out to be cooled by the surrounding atmosphere. The widening of capillaries reduces the blood pressure so that the heart has to work harder in order to move blood through the body. For a lot of people, this extra pressure can cause discomfort, tiredness or minor ill effects when the weather is warm.
Also, the body begins to sweat. As this perspiration cools the body it draws the heat away with it, although it causes large loss of water and salt from the body and the bodies systems will soon not be able to cope.
Common Effects of Heat on the Body
More signs that the body is still trying to cope with heat are: Many signs are minor but are warning signals that could be more dangerous if the body doesn’t cool down quickly.
Other signs include heat rash, small red itchy dots due to sweat ducts being blocked up; swelling of the feet and ankles because the body is not circulating blood around it very well; many people complain of being very tired or headaches or generally feeling weak because the body is trying harder than normal to keep its balance.
The continued loss of fluid and salts without adequate intake could turn the body into suffering from heat exhaustion. Heat exhaustion develops over time and often starts as a mild problem but if the body is not cooled down it develops into serious condition.
Common signs are; Dizziness, feeling nauseous, muscle cramps, sweating a lot, confusion, headaches, feeling faint or extreme tiredness.
Why the Body Reacts This Way to Heat
The body has a relatively small normal operating temperature range, and variations can cause a lot of stress on your body. Thermoregulation is the way that our bodies are able to produce heat through metabolism and release it into the environment to control internal temperature. As the outside temperature increases the blood flow to the body will try to divert towards the outside of the body to release the heat that the internal core is creating, which is why a warm day can cause your body to turn red and warm to touch. The body begins to sweat to cool down. Sweating will remove heat from the body due to the evaporation of water from the skin. Sweat is unable to evaporate efficiently on hot humid days, and dehydration and imbalances of potassium and sodium are issues at these times.
Heat Exhaustion and Heatstroke: The Key Differences
Heat related illness is a spectrum ranging from relatively minor discomfort to a life threatening emergency. The initial stage is commonly heat exhaustion, if this condition is not treated, it can develop into heatstroke. Heat exhaustion generally occurs due to water and salt loss and if the condition is treated quickly through cooling and rehydration the person can recover swiftly. However, if treatment is neglected the body’s mechanisms of regulating temperature fail entirely. Heatstroke occurs at a temperature of over 40C when the cooling mechanisms of the body fail. A person who is suffering from heatstroke may cease to sweat, despite being incredibly hot. They may become confused or begin to seize or may fall unconscious, a doctor must be called immediately. It is important to differentiate between the two conditions, especially in high temperatures during a heatwave, where a number of people can be at risk of dying from this potentially preventable condition.
Who Is Most at Risk During Hot Weather
Specific people are at a greater risk to exposure of heat. For example, elderly people as the body’s temperature regulation is less efficient with age. Infants and babies also gain a higher temperature in hot conditions faster and also do not regulate temperature as efficiently.
For people suffering with conditions such as diabetes or heart problems they also stand at greater risk as for instance a person with diabetes has decreased circulation or may lose fluid and therefore lose water. Conditions such as heart disease put more strain on the body’s circulation and the widening blood vessels of heat exposure.
People who are suffering from certain neurological problems, such as dementia, may be at risk as they might not realize that their body is getting too hot or be able to take any action about it. Homeless people are also exposed to higher temperatures, and people with poor ventilation, such as those on higher floors, or living in inner city areas are at more of a risk from hot conditions.
How Certain Medications Affect Heat Risk
Some medications can make you more vulnerable to the effects of heat by affecting your body’s fluid balance, circulation or ability to cool down. Diuretics, more commonly known as water pills, make you urinate more and can lead to dehydration more easily in hot weather.
Medicines used for blood pressure could lead to your blood pressure dropping when heat-related vasodilation is combined and it can make you dizzy or faint. Some drugs used to treat illnesses like epilepsy and Parkinson’s disease, can affect sweating, thus reducing your body’s ability to cool down naturally.
Some other medicines such as lithium, some treatments for cholesterol, and can increase in concentration in the body when dehydrated, potentially leading to a higher risk of side-effects.
Despite these side effects, medical professionals recommend people do not stop taking prescribed drugs when the weather is hot, but recommend extra care be taken to stay cool and hydrated.
How to Stay Safe During Hot Weather
Being safe in hot weather means reducing your exposure to heat and allowing your body’s natural cooling mechanisms to work efficiently. Easy steps can minimize risks when temperatures rise, such as avoiding direct sunlight at the hottest part of the day by remaining indoors. Keeping rooms cool, especially south-facing rooms, can be done by closing the curtains, or by the use of a fan or good ventilation.
Staying hydrated is also extremely important, so be sure to drink plenty of water throughout the day to compensate for loss through perspiration. Be careful to limit intake of alcohol, as this is de-hydrating.
When outdoors, seeking shade, wearing loose light clothing and high SPF sun block should protect you from the sun. Physical exertion should be minimized during the most intensely warm part of the day, usually between late morning and late afternoon.
During the hottest weather, the well-being of particularly vulnerable groups, such as elderly neighbors and relatives, and young children, should also be checked.
What to Do in an Emergency
People suspected of having heat exhaustion should be given immediate care to stop the condition from developing further. Those affected by heat exhaustion should be moved to a cooler environment and asked to lie down with their legs elevated slightly. Water should be provided and cooling methods such as wet cloths, sprays or fans should be used on the skin. If there is no improvement within 30 minutes, an ambulance should be called, as heat exhaustion may lead into heatstroke. If a person is thought to have suffered heatstroke, emergency services should be called immediately as this is a life-threatening condition.
Conclusion
High temperatures stress the body as they disrupt temperature balance, fluid levels and cardiovascular system and the heart. The human body is able to adjust to modest heat, however severe temperatures are dangerous if precautions are not taken. Knowledge of what can happen to the body, the warning signs and how to help yourself or others stay safe, reduces the chance of serious heat problems. Heatwaves are more common than in many other places and knowledge and preparation of the risks are vital.
