Did MSWG make a good decision to cancel the June 18 event? YES - Read on for Heat Hazard Recognition
Updated: Jun 20, 2022
Recently MSWG canceled the June 18 outdoor TURN-IN event.
Ten members replied with wording such as "Great Call!".
Ron Wickens even sent the image below as part of his comments.
The image got me thinking about some heat-related information members may not know, such as:
Weather services measure temperature and Heat Index in the shade. Being in the sun can make things considerably hotter. Direct sunlight can increase the Heat Index by up to 135°F (7.5°C).
50%-70% of outdoor fatalities occur in the first few days of being outdoors in warm or hot environments because the body needs to gradually build a tolerance to the heat over time, a process called heat acclimatization. Lack of acclimatization represents a major risk factor for fatal heat-related outcomes.
Heat intolerance happens for a variety of reasons. Personal risk factors include:
- Obesity (body mass index ≥ 30 kg/m2)
- High blood pressure
- Heart disease
- Lower level of physical fitness
- Use of certain medications such as diuretics (water pills) and some psychiatric or blood pressure medicines
- Some medications can result in the inability to feel heat conditions and/or the inability to sweat, so symptoms of heat stress may not be evident.
- Alcohol use
Below is the standard Heat Index Conversion Table (you can click on it to enlarge)
Did MSWG make a good decision to cancel? Yes
See the following facts:
On Saturday June 18 at 12 noon the heat index was 100° and climbing
Adding in the direct sun factor (weather was clear) meant adding at least 10° to that reading
On asphalt our members would have experienced an estimated temperature of over 143°
The UV index at 12 noon was 9.5 (considered very high) with the following national weather warning - "Very high risk of harm from unprotected Sun exposure. Alert in effect for 8 hours between 10am–6pm."
Many of the MSWG members who planned to attend are over 60 and many have some type of underlying health issue.
Most if not all MSWG members lack any significant acclimatization to the intense Memphis heat
Give the above-listed effects of heat on the body, attending members would have been exposed to the RED area on the chart above.
What did we learn? MSWG should plan outdoor activities such as the one just canceled during non-summertime months and, if possible, in a covered/well-shaded area.