High heat presents a danger to everyone but if you’ve had a cardiac event you have to pay a bit more attention to the temperature. Medications that slow heart rate reduce the efficiency with which blood flow can help dissipate body heat. Others exaggerate the body’s response to heat. And at no point do you want to make a damaged heart work harder to compensate for excessive exposure to high temperatures.
So, I’m writing this from an air-conditioned room.
The things I needed to get done were finished before lunchtime in the comfort of an air-conditioned car with short walks to and from air-conditioned buildings. I did have to bow out of an event today from noon to 2 pm. It was outdoors during the hottest time of the day.
Not a good idea for me right now.
But I’m never without or far from water because while I am off one of two blood pressure meds they still keep it lower than normal so I need to take in extra fluids to help prop it up. By ‘extra’ I mean a lot of bottled water when it’s not hot out.
This sort of thinking doesn’t just apply to folks with cardiovascular complications. Your body responds to heat the same way as mine if perhaps (depending on your circumstances) more efficiently. So these “rules” offered by groups like Harvard Health and others apply to you as well.
Radiation. Like water flowing downhill, heat naturally moves from warm areas to cooler ones. As long as the air around you is cooler than your body, you radiate heat to the air. But this transfer stops when the air temperature approaches body temperature.
Radiation requires rerouting blood flow so more of it goes to the skin. This makes the heart beat faster and pump harder. On a hot day, it may circulate two to four times as much blood each minute as it does on a cool day.
Evaporation. Every molecule of sweat that evaporates from your skin whisks away heat. On a dry day, the evaporation of a teaspoon of sweat could cool your entire bloodstream by 2 degrees F. But as the humidity creeps above 75% or so, there’s so much water vapor in the air that evaporation becomes increasingly difficult.
Evaporation also strains the cardiovascular system. Sweat pulls more than heat from the body—it also pulls out sodium, potassium, and other minerals needed for muscle contractions, nerve transmissions, and water balance. To counter these losses, the body begins secreting hormones that help the body hold onto water and minimize mineral losses.
For people at higher risk,
- Damage from a heart attack can keep the heart from pumping enough blood to get rid of heat.
- Cholesterol-narrowed arteries can limit blood flow to the skin.
- Medications interfere with heat regulation. Beta blockers slow the heartbeat, and so limit the heart’s ability to circulate blood fast enough for effective heat exchange. Diuretics (water pills) make dehydration worse by increasing urine output. Some antidepressants and antihistamines can block sweating.
- A stroke, Parkinson’s disease, Alzheimer’s disease, diabetes, and other conditions can dull the brain’s response to dehydration. So it may fail to send thirst signals.
And the heart association has some added points on heat exhaustion and heatstroke of which everyone should be aware.
Symptoms of heat exhaustion:
- Headaches
- Cool, moist skin
- Dizziness and light-headedness
- Weakness
- Nausea and vomiting
- Dark urine
If you experience these symptoms, move to a cooler place, stop exercising and cool down immediately by using cool wet cloths, compresses, and fanning. You may need to seek medical attention.
Symptoms of heat stroke:
The symptoms of heatstroke include (call 911 or the local emergency number right away):
- Fever (temperature above 104 °F)
- Irrational behavior
- Extreme confusion
- Dry, hot, and red skin
- Rapid, shallow breathing
- Rapid, weak pulse
- Seizures
- Unconsciousness
If you experience these symptoms, seek medical attention right away.
To avoid them have water with you don’t just pan to pick some up in your travels. Why? If you start to experience any of these symptoms you are already dehydrated. Healthy folks can fix it quick enough but the headache may stay with a you a while. Avoid it by sipping or drinking water often, even of you don’t feel thirsty, especially when it’s hot out. And this week is going to be hot.
It’s 4th of July week and New England will experience 90+ degree days through the Holiday. If you are going to be outside in the heat make sure you watch for these symptoms not just for yourself but for kids, the elderly, and anyone with health complications that might be more adversely affected by high temperatures.
If you drink alcohol, even just beer, drink at least one bottle of water in between beers or other adult beverages.
If you’ve got a health complication get advice from your healthcare professional about dealing with the heat so you can have a safe week and a Happy Independence Day!
