People like landscapers, construction workers and restaurant line cooks work in hot conditions regularly — but how does that impact their health?

According to the EPA, multi-day heat waves are expected to get longer in the future, and reach higher temperatures.

Researchers at Boston University are leading multiple studies about the health impacts of heat, including for people who face hot conditions on the job and in early childcare settings. To discuss that research, GBH’s Morning Edition guest host Craig LeMoult spoke with Dr. Madeleine Scammel, a professor at BU School of Public Health and co-principal investigator on the C-HEAT study. What follows is a lightly edited transcript.

Craig LeMoult: So who are the workers that you’ve been studying this summer? What kind of jobs do they have?

Dr. Madeleine Scammell: We have a pilot study of workers. Many of them are cleaners in homes and office buildings, a restaurant worker, construction worker, [and] a painter.

LeMoult: And you’re monitoring the effect of the heat on them this summer — how are you doing that?

Scammell: We’re monitoring the heat period — so [things like] core body temperature, immediate ambient temperature and what they experience at work [and their symptoms].

Then we’re giving them a little bit of an intervention, or something that they can use to cool themselves. [That includes] a cooling vest that would be kept in a cooler until they want to put it on — and would work for about four hours to cool their body temperature. Nobody chose that option — what they chose are the fans that they wear around their neck, and a fan that you can put on your belt that actually sends mist up your chest, and then a bandana or a cooling towel.

And we will monitor them for three weeks with the devices.

LeMoult In terms of the temperature data, do we know how hot it’s been for them?

Scammell: We haven’t yet looked at the data. I will say some of the things we’re looking for is how much time they spend above the 38 degree threshold of core body temperature. Any [workplace] standard that may exist or guidelines for protecting workers are meant to protect them from their core body temperature exceeding 38 degrees Celsius.

LeMoult: What kind of legal safety standards exist for heat exposure at work?

Scammell: Very few, depending where you are. There’s nothing at the federal level and that’s a work in progress.

The Occupational Safety and Health Administration actually has published a draft standard to protect workers from extreme heat. I don’t know what will happen to that going forward. But at states and in municipalities, including in Boston and in Massachusetts, there is legislation that has been proposed — ordinances meant to protect workers from extreme heat at the workplace.

LeMoult: What can employers do? What kind of changes can they make, to ensure that people are safe?

Scammell: That’s the key question in my mind. We can’t eliminate heat — that would be the first thing. But what we can do are engineering controls that would provide more cooling and ventilation, especially for indoor workers. That’s a real possibility.

In particular, house cleaners and office building cleaners, when they go into the building to do the cleaning, the owners turn the AC off because the day workers are gone, and that makes it really hot. So businesses could change their practices to protect the workers who they’re contracting, usually, to come in and clean their buildings.

For outdoor workers, there could be more administrative controls, like building in redundancy, and having more people do jobs that, in less extreme temperatures, fewer people could do without tiring. But we need to build in breaks, and we need to build in places where people can cool down.

LeMoult: What are the health concerns from this kind of heat exposure?

Scammell: When you overheat, you basically run the risk of cooking your organs, including your brain. And so the minute you feel excessive sweating and dizziness, these are the signs and symptoms of heat exhaustion, nausea, and even vomiting. Heat stroke manifests through irrational behavior and confusion — sometimes people mistake it for the kind of stroke that we more typically see in older adults, or drug overdoses.

"When you overheat, you basically run the risk of cooking your organs, including your brain."
Dr. Madeleine Scammell, Boston University researcher

What relates to workers in particular that I’m concerned about is the higher rates of injury on the job — so people who work with heavy machinery and with knives in kitchens. Your reaction time is delayed when you’re experiencing extreme heat, and injury rates definitely increase with temperatures.

LeMoult: Your occupational research this summer is not being funded by the federal government, but I know some of your other research has been funded that way. With all the grant terminations that are happening nationally, how has your work been affected?

Scammell: I will just say, yes, the work that we’re doing that I’ve described here is funded by the Barr Foundation. The changes at the NIH and EPA have really affected my work personally, and work throughout the BU School of Public Health.

I got into studying heat in Massachusetts because I study heat among workers in Central America. We’ve been doing research in Nicaragua for 15 years or more, and the federal government is no longer supporting anything in Nicaragua. We’ve had to stop our research in Nicaragua altogether.

We’ve had to pause all of our field work in El Salvador and all the other places, all the countries involved in this consortium — which is a real problem when you’re doing research that involves people with a disease in particular, but anybody, you want to engage them, you want keep them updated, you wanna follow them, that’s one of our objectives and we’ve lost staff because we can’t pay them.

The third way that the terminations have affected our research is that one of my brilliant students was funded to work with us in this realm through a grant to increase diversity for people who are underrepresented in our field — and that was terminated.

LeMoult: I can imagine research on the health effects of extreme heat is becoming even more important, as we see summers getting hotter and hotter?

Scammell: I think you’re right. I think 2024 was record-breaking across the globe in terms of the heat we experienced. 2025 has been hot. In Massachusetts, we broke our record for the hottest day in June since we’ve been tracking our temperatures. So I think we do have to acknowledge that climate change is real. But if we refuse to do that, maybe we need to acknowledge that heat is something that people suffer from, and the number of hot days are increasing.