Caution over electric fans and other heatwave survival tips

For those wondering how to survive the heat, look no further.

Here is a very handy reference, the “Excessive Heat Events Guidebook”, produced by the Environmental Protection Agency in the US in 2006.

It contains a wealth of useful information, for individuals, health services, planners and policy makers.

Extreme heat events should be taken seriously as a threat to public health – it notes that more than 15,000 deaths in France alone were attributed to extreme heat in August 2003 – but the risks can be reduced with some planning and effort.

Those at highest risk from such events are:

• Older people (age > 65)
• Infants (age < 1)
• The homeless
• The poor
• People who are socially isolated
• People with mobility restrictions or mental impairments
• People taking certain medications (e.g., for high blood pressure, depression, insomnia)
• People engaged in vigorous outdoor exercise or work or those under the influence of drugs or alcohol.

The guide says that public authorities should consider:

• Establishing and facilitating access to air-conditioned public shelters

• Ensuring real-time public access to information on the risks of the extreme heat event conditions and appropriate responses through broadcast media, web sites, toll-free phone lines

• Establishing systems to alert public health officials about high-risk individuals or those in distress during an extreme heat event (eg, phone hotlines, high-risk lists)

• Directly assessing and, if needed, intervening on behalf of those at greatest risk (eg, the homeless, older people, those with known medical conditions).

The guide also lists some of the strategies used in Philadelphia, which has been dubbed the “heat death capital of the world” (and you thought it was Melbourne…), including:

• Coordinate public broadcasts of information about the anticipated timing, severity, and duration of extreme heat event conditions and availability and hours of any public cooling centers

• Coordinate public distribution and broadcast of heat exposure symptoms and tips on how to stay cool

• Operate informational phone lines that can be used to report heat-related health concerns

• Designate public buildings or specific private buildings with air conditioning as public cooling shelters and provide transportation

• Extend hours of operation at community centers with air conditioning

• Arrange for extra staffing of emergency support services

• Directly contact and evaluate the environmental conditions and health status of known high-risk individuals and locations likely to have concentrations of these individuals

• Increase outreach efforts to the homeless and establish provisions for their protective removal to cooling shelters

• Suspend utility shutoffs

• Reschedule public events to avoid large outdoor gatherings when possible.

Now for the electric fans caution: The authors also strongly recommend that public education programs should emphasise that portable electric fans are not the simple cooling solution they appear to be.

The guide says: “Because of the limits of conduction and convection, using a portable electric fan alone when heat index temperatures exceed 99°F actually increases the heat stress the body must respond to by blowing air that is warmer than the ideal body temperature over the skin surface.

In these conditions, portable electric fans provide a cooling effect by evaporating sweat. The increased circulation of hot air and increased sweat evaporation can, however, speed the onset of heat-attributable conditions (eg, heat exhaustion). Thus, portable electric fans need to be used with caution and under specific circumstances during an extreme heat event, such as exhausting hot air from a room or drawing in cooler air through an open window.

Generally, portable electric fans may not be a practical and safe cooling mechanism during an extreme heat event in homes that are already hot and are not air-conditioned; their use should be discouraged unless the fans are bringing in significantly cooler air from outside the dwelling.

If a resident must stay in these dwellings, and if they are unableto access an air-conditioned environment, safer cooling approaches would include taking frequent cool showers and drinking cool, nonalcoholic fluids (e., ice water).”

But it’s not all about short-term relief. The guide also recommends long-term solutions, including urban design and development programs to help control the development of “urban heat islands”.

The guide notes that beating the heat doesn’t necessarily cost a lot; it just requires some planning and juggling.

“Experience in several North American cities has demonstrated that comprehensive and effective extreme heat event notification and response programs can be developed and implemented at relatively low cost. These programs generally use available resources instead of creating extreme heat event-specific institutions. This approach recognizes that short-term resource reallocations for extreme heat events are justified by the severity of their public health risks, the limited duration and frequency of the events, and the cost-effectiveness of the reallocations.”

Meanwhile, this is a relevant .

And for the WHO Regional Committee for Europe cites Centers for Disease Control and Prevention guidelines on surviving heat. Recommendations include:

• Drink more fluids (nonalcoholic), regardless of your activity level. Don’t wait until you’re thirsty to drink. Warning: If your doctor generally limits the amount of fluid you drink or has you on water pills, ask him how much you should drink while the weather is hot.

• Don’t drink liquids that contain caffeine, alcohol, or large amounts of sugar – these actually cause you to lose more body fluid. Also, avoid very cold drinks, because they can cause stomach cramps.

• Stay indoors and, if at all possible, stay in an air-conditioned place. If your home does not have air conditioning, go to the shopping mall or public library – even a few hours spent in air conditioning can help your body stay cooler when you go back into the heat. Call your local health department to see if there are any heat-relief shelters in your area.

• Electric fans may provide comfort, but when the temperature is higher than 35 °C, fans will not prevent heat-related illness. Taking a cool shower or bath, or moving to an air-conditioned place is a much better way to cool off.

• Wear lightweight, light-coloured, loose-fitting clothing.

• NEVER leave anyone in a closed, parked vehicle.

• Visit adults at risk at least twice a day and closely watch them for signs of heat exhaustion or heat stroke. Infants and young children, of course, need much more frequent watching.

In other words, there seems to be plenty of available information for how to reduce the impact of heatwaves, at both the population and individual level.

I guess time will tell how well prepared we are.

Thanks to the always timely and relevant Health Impact Assessment blog for the lead on these resources.