Beating heat as a general public health issue so as to stay safe under climatic conditions of hot weather is a major worldwide issue not to be ignored for its past intervention on human health hasn’t been friendly for exposing self under high temperatures can be seriously harmful to your health as was observed in one hot spell in August 2003 in England and Wales there where over 2,000 additional deaths than what would normally be expected under normal circumstances, the heat can affect anyone but some people run a greater risk of intense harm than others as they often expose their selves without protection under the hot heat spells casted out by the sun on to our wonderful planet Earth.
Stay cool in heat
Many take it lightly when they are asked to stay cool in heat, this might be because they are not aware of the different health risks they are exposing self to when they neglect the processes of staying cool in heat, so it is of primary importance before moving to the different ways of keeping self-cool in hot climates we discuss on concrete reasons why we should stay cool in hot climates and the things we are protecting self from;
Sunlight contains ultraviolet rays in large quantities which is a major cause of premature aging of the skin, cataracts, wrinkles, and serious skin cancer so it is of primary importance staying cool in heat. There exist no save ultraviolet rays neither safe suntans. So one should pay special care to the skin if he/she burn easily under the sun, spend a lot of time outdoors, or who has any or more of the following features; irregular, numerous, large moles, freckles, fair skin, blond, light brown hair should all follow the steps below on blocking the harmful rays from the sun;
- Should cover up, wear just loose fitting, long pants and long sleeved shirts.
- Use the sunscreen together with a sun protective factor which is of at least 30 making sure one is following the application directions on the bottle or tube.
- Making sure one wears a hat that is a wide brim hat, not the baseball cap we all know, which works best because it protects the neck, ears, eyes, forehead, scalp and nose.
- Making sure one wears ultraviolet absorbent sunglasses which don’t have to be obviously expensive, but are able to block 99% to 100% of UVA and the UVB radiations which are detrimental to one’s health, one should always read the product tag or label before buying sunglasses.
- Ultraviolet rays are most intense between 10 am and 4 pm be well protected against.
Ways to stay cool
Most life’s working conditions and jobs often exposed the job executer to space heat coming from the sun which is not only destructive to the environment when in high intensities but also is a threat to human life so let’s discuss on some ways of keeping ourselves cool under this harsh conditions which can destroy our health not forgetting it can affect anyone. But some people run a greater risk of harm like old people over 75, the young and people who are already in a dehydrated health conditions.
One of the primary step in staying cool know the weather forecast which is possible with our increasing scientific technologies. These forecasts are often given on most national television stations can help you better plan ahead and adapt easily to keep cool whenever the temperatures increase.
Working under hot conditions one should avoid taking drinks with alcohol, caffeine, tea, coffee and cola just before the work or during working hours for these drinks increase body dehydration which shall deprive you of the body water necessary to keep your body cool as temperatures increase at your working site.
In working outside under heat it’s very important to keep with you cold drinks to take often so as to maintain body temperatures as the heat increases, avoid too much sugary drinks as might lead to dehydration, in case you are taking fruit juice it’s advisable to dilute it with water so as to reduce its sugary intensity.
Eat cold foods especially salads and fruits with high water contents, not to forget drinking enough water is of primary importance as to keep the body hydrated and cool.
During the summer months, a combination of heat and humidity can be a serious health threat which should not be taken lightly, if one is working outside for example, at a construction site, beach and working in the farm or doing any other thing that exposes one under the heat of the sun then one should consider taking the following precautions;
- Frequently take in small amounts of water by drinking.
- Make sure clothing is light coloured, loose fitting, breathable and if cotton made then it is of added advantage.
- Frequently take short breaks in cool shades.
- Consume just small meals before activities.
- Avoid sugar in large quantities, caffeine and alcohol.
- If possible work in the shade.
- Check from your health care if your medication and heat doesn’t mix.
- Be aware of the fact that equipment such as respirators and other work suits can increase heat stress greatly.
Cooling clothes for hot weather
Dressing appropriately is one of the major tools of keeping self-cool under a hot weather, so one should be careful on the kinds of clothes he/she puts on for working under hot weathers for its advisable to wear clothes made up of light coloured cotton and are loose-fitting like long-sleeved shirts for science has proven that such clothes reflect and not refract neither absorb light thus keeping your body cool under your working activities till the end.
Extra body dressing can be of extreme importance in keeping cool under hot weathers such as wearing a suitable head wear like a wide brimmed-hat thus reducing exposure of face, head, and neck to the direct sun rays bringing in the body increase temperatures, you can also get sun glasses which exclude both direct and peripheral exposure of the eye to ultraviolet radiations.
In order to adapt with the rapid technological advancement all round the world, human has completely accepted the challenges in increasingly adverse and hostile conditions. Notwithstanding the growth of technology, places still exist where we have to work in humid or/and hot conditions around the world, whereby we have the action of two stress factors acting together in such cases, via the work load and other hot environmental conditions. Some examples of such work areas include firefighting, chemical warfare conditions, and aerospace, working in foundry, mines and desert regions around the world.
One of the potential fatal occupational hazard is exposure to high temperatures during working, all personnel working in such harmful conditions are condemned to suffer from heat strain and even heat stroke in extreme cases. In the process of protecting the personnel from such physiological disorders, so often a two-step approach is adopted;
Firstly, a good heat protective suit is worn by the worker which acts as a shield against the incoming radiative heat having it origin from the hot environment outside. Inappropriately these types of protective equipment impede dissipation of metabolic heat generated as a result of work, in the process of removing this metabolic waste cooling garments have proven to be the best, as they play an important role in alleviating the thermal discomfort experienced by all the individuals working in this hot adverse environmental conditions. The functioning principle of these cooling garments is creating a cooler microclimate thereby facilitating the removal of metabolic heat and also blocking heat exchange between the user and his environment. The cooling garments can broadly be classified in to two large groups based on their working principles and strategies, namely active and passive cooling garments,
The principle of active cooling garments is functioning by circulating cool air or liquids through the turbine networked found inside the garments, its mode of heat transfer is mostly by conduction and convection.
Whereas passive cooling garments use either phase change materials like ice packs, paraffin waxes, polymer gels, evaporation of cooling liquids and chemical frozen gels.
Secondly is by human thermoregulations, which is the literal meaning of homeostasis meaning same state, referring to the control of the inner body temperatures when external environment is changed, we have one of the largest examples of homeostasis being human thermoregulation of human body temperature within a very narrow range. We have human thermoregulation not only controlling internal temperatures but also the external heat dissipation. Its overall requirement is actually balancing between heat input and heat output of the body, for any imbalance between the heat gain and the heat loss will lead to a thermal discomfort, still the thermal comfort is not dependent on energy balance alone, along with it is a secondary requirement which is the combination of core body temperature and skin body temperature to give thermal neutrality,
When body temperature is actually controlled with just minimum physiologically regulated efforts we have the occurrence of a sensation of thermal comfort.
Clothes that keep you cool
Active cooling garments:
As we had previously discussed earlier, active cooling garments function on the principle of circulating cool air or liquids all through tubing spread in the garment so as to regulate body temperature when one is working under hash climates. These type of garments are also referred to as fluid cooling garments or the FCG, these active cooling garments are further divided in to two categories, which are air cooled garments and liquid/water cooled garments.
Air cooled garments: In an air cooled garment, we have compressed air being supplied from the external air supply system whereby the process of heat removal takes place through evaporation of sweat and through convection. We have miniature jets at the end of every distribution pipe which are provided to break up the air layers thereby promoting the sweat evaporation process. These garments depending on their application can employ pre cooled air or ambient air. The Gemini and Apollo space suits are functional based on this type of body cooling, whereas different researches have proven the Gemini space suits are of a very limited cooling capacity as the cooling was marginal for work rates above 348.9 watt for minor improvements on cooling efficiency often lead to uncomfortable wind and noise stages.
Advantages of air cooled garments:
- Being a positive pressure system a little tear or leak in the garments is less likely to contribute in the contamination of the wearer.
- It is easier to connect and disconnect as compared to other systems like liquid systems.
Disadvantages of air cooled garments:
- We have it cooling efficiency being inferior due to low heat capacity of air.
- Being heavy and bulky it needs continuous power supply.
Liquid cooled garments: Due to the failure of air cooled garments in providing desired cooling efficiency in specific applications like space working, specific applications like space suits lead to the development of liquid cooled garments which are the most active cooling garments used in today’s applications, in all liquid cooling garments, there is the circulation of cooling liquid inside the tubes embedded in the garments structure by means of battery operated pump. Cooling efficiency of all liquid cooling garments depend on the environmental conditions, length and tubing type, inlet liquid temperature, flow rate and flow pattern. The external heat can be indirectly be absorbed by the garments or reach the tubing. Apart from air temperature, humidity plays a great important role in controlling the cooling capacity of the liquid.
Passive cooling garments:
All passive cooling garments generally use either phase change materials like paraffin wax, ice, chemical frozen gels and evaporation of cooling liquids which are normally water. Base on the material type used, passive cooling garments are divided in to two namely; (i) garments with phase change materials and (ii) the evaporative cooling garments.
- All phase change cooling garments often use dry ice or ice as the coolant, we have the body core skin temperature formed due to the cooling effects of ice or dry ice through the latent heat of melting together with the latent heat of sublimation, as a result body cooling mainly takes place through conduction.
- In talking about evaporative cooling garments we notice cooling from water soaked garments has been discovered shortly after clothes became standard for human beings, obviously the effect of cooling from wet clothing is a pleasing one, but for daily use it might have an inconvenience as the wet cloth easily dries up under a strong breeze and action of sun.