Protecting people’s health from summer heat

WHO/A. Kari

Summer 2013 has definitely arrived and people are quite busy enjoying their “cool biz” activities and, for others, preparing for their much-awaited “natsu-yasumi” (summer vacation). Yet, caution and prudence are necessary as exposure to excessive heat has been a growing public health risk – for every degree Centigrade above a threshold level, deaths can increase by 2 to 5 percent.

Ten years ago, the extended heat of the European summer 2003 caused a rise in death rates that was 4 to 5 times higher than expected levels at the peak of the event in some cities, eventually causing over 70 000 additional deaths across 12 countries. Contributing to the heightened risk was the phenomenon called “urban heat island effect” which can raise temperatures by more than 5°C in urban settings compared to rural settings. High temperatures, as we are aware of, exacerbate the harmful effects of ozone and particulate air pollution.

Another reason for concern is that population growth, ageing and urbanization are considered factors expected to increase the number of people at risk of heat stress. By 2050, it has been estimated that there will be at least 3 times as many people aged 65 and above living in cities within developing regions having the greatest increases. Also by the 2050s, heat events that would currently occur only once every 20 years will be projected to occur on average every 2-5 years. These would make heat stress and its management a global-national-local health challenge and priority for the coming decades.

A technical report entitled “Protecting the public and minimizing health effects from heat: towards the development of a Heat-Health Action Framework for the Prefecture of Hyogo, Japan” (WHO, 2013) was published in May 2013.

This was developed in support of efforts by the prefectural government of Hyogo, Japan towards a comprehensive system for public health prevention of heat disorders. It was the result of an evidence-building process involving relevant stakeholders in Japan as a response to the call by the Governor, Hyogo Prefecture, Japan for further action to prevent health effects from heat waves and from climate variability and climate change.

What is needed, indicated by lessons learned from evidence and experience, is a close collaboration between climate and health and health-related services, at different levels, to confront emerging environmental health challenges. For example, following the 2003 heat waves in Europe, 17 countries have so far established their heat-health action plans.

At the local level, weather forecasts can now routinely provide information not only on warnings when high temperatures may become hazardous to health but also information on levels of ozone and particulate air pollutants, pollen and exposure to ultraviolet radiation. When services are properly connected or integrated with guidance and plans for action, the system would enable individuals and communities to avoid or limit harm to health and, therefore, protect health.

At the individual level, it is important to be reminded about the following updated proposed tips for dealing with heat during summer:

  • Be prepared to adapt to heat and behave appropriately.
    • Limit sun exposure during midday hours.
    • Drink lots of fresh water, regularly.
    • Wear smart, lightweight, short-sleeved, loose-fitting, cotton clothing (Practise “cool business”/”cool biz”).
    • Use sun protective products when outdoors.
    • Eat fruits and vegetables; avoid heavy meals, alcoholic drinks and too much coffee.
    • Refrain from smoking.
    • Know the signs and symptoms of heat disorders and be ready to give first aid treatment, as appropriate.
  • Pay attention to your environment.
    • Adjust the setting of your air conditioner at home or in the office as close to the outdoor temperature as possible, up to 28°C. Use of fans is encouraged.
    • During the hotter times of the day, keep your windows shaded, if there is direct exposure to the sun. Seek shade.
    • Turn off unnecessary heat-producing devices (e.g., incandescent light bulbs, etc).
    • Keep yourself informed of health advisories by listening to local weather and news channels or by contacting local health departments.

Extreme heat can be damaging to health, and may endanger the lives of the more vulnerable: babies, young children, older people, the poor, the homeless, the medically frail, and those with disabilities. The fact is that any person can be at increased risk from heat, especially for those who participate in strenuous physical activities during hot weather.