As part of my Weather & Wellness Wednesdays blog series, I plan to explore how current weather, climate, and water-related events impact our health. With this week (May 19-23, 2025) being designated as Heat Safety Week by the National Integrated Heat Health Information System (NIHHIS), I think it's the perfect time to spotlight a couple of dangers that are sometimes overlooked: early-season and moderate heat.
When most people think about health issues caused by heat, they picture extreme temperatures such as sweltering days in the upper 90s or over 100°F. However, even moderate heat can be hazardous, especially early in the season before our bodies have had time to adapt.
Early Season Heat and Acclimatization
Last week, southeast Louisiana experienced its first real taste of summer: temperatures were in the 90s, humidity was high, and heat indices skyrocketed. On May 13, 2025, The National Weather Service in New Orleans included health-specific guidance in their Area Forecast Discussion (AFD) due to the early-season heat:
I was excited to see this messaging from our local NWS office! As someone passionate about the intersection of meteorology and public health, it was encouraging to see acclimatization mentioned in a forecast. The American Meteorological Society (AMS) defines acclimatization as: “The process by which a living organism becomes adapted to a change of climatic environment.” According to the CDC, it can take up to 14 days for the human body to fully acclimate to high temperatures. During that time, the body undergoes changes in thermoregulation like learning to sweat more efficiently and sooner.
Early-season heat may not bring the scorching temperatures that you may see in July and August, but it can still pose serious health risks. Because the body has not adapted to the increasing temperatures, people may be susceptible to heat-related illnesses such as dehydration, heat exhaustion, or even heat stroke. Those vulnerable to early-season heat not only include those who work outdoors and the elderly, but also vacationers in warm weather destinations and students who relocate to attend college and universities in climates that are warmer than what they are accustomed to.
Moderate Heat Is Not a Minor Issue
During the summer months, extreme heat or long-duration heatwaves usually get the eye-catching news headlines. However moderate heat, even temperatures and heat indices below heat advisory thresholds, have proven to be dangerous as well.
During the American Public Health Association (APHA) Annual Meeting in Atlanta in 2017, I attended a environmental health session regarding moderate heat and public health which featured representatives from the Northeast Regional Heat Collaborative. This collaborative included public health officials from Maine, Vermont, New Hampshire, and Rhode Island. Research from this group showed that there were significant increases in emergency department visits that were associated with heat index values below advisory thresholds. Residents in New England can be particularly susceptible to moderate heat because the use of air conditioning is lower in that area than in other parts of the country. To address this issue, the Northeast Regional Heat Collaborative worked with the National Weather Service to lower the heat advisory threshold in parts of New England. This, in my opinion, was a wonderful example of how public health and safety organizations can work together to ensure healthier populations! You can find the abstract of this presentation at this link: https://apha.confex.com/apha/2017/meetingapi.cgi/Paper/376327?filename=2017_Abstract376327.html&template=Word
Heat Safety Measures
So now that we know that both early-season heat and moderate heat can take a toll on our health, how can we prepare and stay safe?
- Be Weather Aware. I will probably state this in every single Weather and Wellness Wednesday Blog! It's very important to stay aware of weather forecasts and outlooks. For example, in addition to reading local NWS forecasts and watching local broadcast meteorologists on television, I also pay attention to the 8-14 day temperature outlooks from the NWS Climate Prediction Center. Forecasts and outlooks can help you prepare for warmer weather. This is especially important if you are planning outdoor activities.
- Limit outdoor activities during peak heating hours (if possible). These peak hours are typically between noon and mid-afternoon.
- Hydrate regularly. It's important to drink water even if you don't feel thirsty. Avoid caffeinated and sugary drinks. Staying hydrated is essential for those who take diuretics for health conditions.
- Wear light breathable clothing. Light colored linen and lightweight cotton materials should be closet staples during warm months.
- Use fans or air conditioning if possible. Federally funded programs such as the Low Income Home Energy Assistance Program can help eligible individuals with energy bills or help with purchasing or repairing an air conditioning unit.
- Discuss heat dangers with health care providers. Speak with your doctors to learn if you are susceptible to heat-related illnesses due to a chronic health condition or medications.
- Be a good neighbor. Check in with your neighbors during warm weather, especially those who are elderly, have mobility issues, or live alone.
Final Thoughts
Heat is a complex issue. One size does not fit all in regards to health effects from heat exposure. Let me know your thoughts on the dangers of early-season and moderate heat! I will be diving into additional heat topics as the summer months approach.
Sources:
https://communityresilience-center.org/wp-content/uploads/2017/03/Dealing-With-Extreme-Heat.pdf
https://www.cdc.gov/climate-health/media/pdfs/2024/06/NORTHEAST__Regional_Factsheet.pdf
https://www.cpc.ncep.noaa.gov/products/predictions/814day/index.php
https://www.cdc.gov/niosh/heat-stress/recommendations/acclimatization.html
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