November 2024: Simple Strategies to Reduce Cardiac Strain in Older Adults in Extreme Heat
The issue
Extreme heat places older adults — especially those with heart disease — at high risk of dangerous spikes in heart rate and blood pressure. Simple cooling tactics such as electric fans and skin wetting have been debated, but their true benefits and harms were unclear.
What do I need to know?
Researchers exposed seniors with and without coronary artery disease to three‑hour heat sessions at 38 °C / 60 % humidity and at 45 °C / 15 % humidity. In the humid setting, fan use, skin wetting, or both together lowered the rise in rate–pressure product (a measure of cardiac strain) by 468‑750 bpm·mm Hg compared with no cooling. In the very hot, dry setting, fan use tripled cardiac strain and led 43 % of participants to stop early, while skin wetting alone still reduced strain by about 480 bpm·mm Hg. Overall, the study supports fans and skin wetting up to 38 °C with high humidity, and skin wetting (but not fans) at 45 °C with very low humidity.
Potential risk of heat‑related cardiac strain
Older adult lives in a home that can reach 32–38 °C but still has some ventilation or shade.
Recommended Actions
Check local heat forecasts and schedule outdoor or strenuous activities for cooler hours.
Use a fan plus frequent skin misting or damp cloths when indoor temperature stays below 38 °C.
Encourage hydration and light clothing.
Imminent risk of heat‑related cardiac strain
Heatwave forecast of ≥ 38 °C with high humidity or ≥ 40 °C dry air; no air‑conditioning; history of heart disease.
Recommended Actions
Prioritize skin wetting every 30 minutes and keep a spray bottle nearby.
Move to an air‑conditioned friend’s home, cooling center, or shaded public venue during peak heat.
Avoid fan use if indoor air is > 45 °C and very dry; instead rely on skin wetting or cool showers.
Monitor heart rate and symptoms; have emergency contacts ready.
Confirmed heat‑induced strain
Older adult develops rapid pulse, chest discomfort, dizziness, or blood‑pressure spikes while in extreme heat.
Recommended Actions
Call emergency services if chest pain, fainting, or severe shortness of breath occurs.
Cool quickly: apply cold wet towels to neck, armpits, and groin; use a fan only if air is not extremely hot and dry.
After stabilization, arrange cardiology follow‑up and review heat‑safety plan.
What can I do?
Ask the doctor, “Am I at potential, imminent, or confirmed risk from heat, and which cooling method is safest for my home conditions?” Keep a thermometer indoors; if it stays under 38 °C, a fan plus skin wetting is effective, but at 45 °C with dry air switch to skin wetting alone. Record episodes of dizziness, fast pulse, or fatigue during heat exposure and share them at medical visits. Caregivers should check on older relatives twice daily during heatwaves and ensure easy access to water, a spray bottle, and a cool refuge.
