A little reminder about staying safe during the heatwave

[Kickapoo Kicker]

I know pretty much everyone knows this stuff, but it doesn't hurt to have a quick little refresher course...especially now.

From the BBC

Heat Effects

Obviously there is the risk of sunburn, but there are many more heat disorders that can strike. In high temperatures humans sweat to cool down. Sweat evaporates from the skin removing excess heat. Logically you sweat more in hotter climates, and the body tries to adapt to the climate by adjusting the amount of salt in the perspiration.

Salt is essential to the body as it helps the cell tissues to retain water. The body must retain the necessary salt levels in the cells, whist cooling the body to 37°C (98.6°F). If the body loses too much salt or water it can become life-threatening.

Humidity can significantly add to the 'apparent' temperature by reducing the body's ability to cool itself down. At 24°C, (75°F), and a humidity of over 50 percent the body experiences a temperature greater than that of the actual thermometer reading, increasing the threat of heat stress.

Excessive sweating can lead to painful muscle spasms called heat cramps, or to heat exhaustion, which has many symptoms including excessive thirst, dizziness and nausea. Both can be treated by drinking water and resting in a cool place, but heat stroke requires urgent medical attention. The body's thermostat stops working, so sweating is significantly reduced, or can stop altogether, and the body's temperature becomes very hot (sometimes over 40°C, 104°F).

Heat stroke is less common in the British Isles than in other countries nearer the Tropics, as our Summers are relatively mild. Heat rashes are far more common. This is not just an itchy rash, but it also reduces the body's ability to sweat making heat less tolerable.

People do gradually acclimatise to hotter climates. The body's perceived exertion and heart rate all adapt with time, but some insects and animals can adapt much better. Studies on locusts from cool climates revealed that they have trouble flying, or even die, if released into hot deserts unless they have been previously exposed to the heat for a short period. Brief exposure to high temperatures has a lasting effect on their nervous system and it is these changes that could enable animals to fly in very hot environments.

 

[Bird Guano]

More good info....

http://www.emedicine.com/ped/topic556.htm

Table 1. Clinical Findings of Dehydration
Symptom/Sign

Mild Dehydration Moderate Dehydration Severe Dehydration

Level of consciousness* Alert Lethargic Obtunded

Capillary refill* 2 Seconds 2-4 Seconds Greater than 4 seconds, cool limbs

Mucous membranes* Normal Dry Parched, cracked

Tears* Normal Decreased Absent

Heart rate Slight increase Increased Very increased

Respiratory rate Normal Increased Increased and hyperpnea

Blood pressure Normal Normal, but orthostasis Decreased

Pulse Normal Thready Faint or impalpable

Skin turgor Normal Slow Tenting

Fontanel Normal Depressed Sunken

Eyes Normal Sunken Very sunken

Urine output Decreased Oliguria Oliguria/anuria
* Best indicators of hydration status

Table 2. Estimated Fluid Deficit
Severity Infants (weight <10 kg) Children (weight >10 kg)
Mild dehydration 5% or 50 mL/kg 3% or 30 mL/kg
Moderate dehydration 10% or 100 mL/kg 6% or 60 mL/kg
Severe dehydration 15% or 150 mL/kg 9% or 90 mL/kg

 

[night driver]

Umm sorry but CApilary Refil isn't a good indicator of anything really. We've found that it really doesn't corelate to squat in the Prehospital Arena.

In the field, in Operational Arenas, we use LOC, Mucous Membranes, and urine output as our triggers and evaluators....and these are not exactly EARLY signs, though they are early-ish signs that yer in TROUBLE.

Urine output is what we like to hang our hats on. Clear, Copious and frequent are what we like to see (meaning once in the morning and once in the afternoon and we're going to be discussing rehydration techniques)

 

[lynnie]

Once in the morning and once in the afternoon is frequent, Chuck?

If that happened to me I'd think my kidneys were failing. Middle age bladder here.

 

[A.T.Hagan]

Good reminder.

In the United States year after year heat deaths outnumber all other forms of death from natural disasters. They tend to come in small numbers though and mostly to the very old and the very ill so they never get much newsplay. I think California is around a hundred or so for this year alone and the rest of the country probably brings the total up to around two hundred.

.....Alan.

 

[baw]

We're looking at the heat index to peak to 110° today and tomorrow here in WI. With the humidity. aghhhh

 

[A.T.Hagan]

Moved to Preps.

.....Alan.