Could night shifts be the answer to rising temperatures?

Our planet is getting hotter. New research suggests that July 2023 is likely the hottest Earth has been in 120,000 years. This warming is expected to trend upward. The BBC reported that in the future, summers could make certain places uninhabitable for humans due to the extreme heat. Even now, heat waves can threaten the lives of many people. The 2022 European heat wave is estimated to have killed 62,000 people.

Currently, 64 per cent of Canadians have air conditioning to deal with this extreme heat. That said, air conditioning has been called an unsustainable, unrealistic tool to combat heat wave-related climate change.

This problem is multifaceted, partly because air conditioning units contribute to carbon emissions. Higher air conditioning usage would contribute further to climate change, creating a feedback loop.

Another consideration is power usage. Canada’s energy surplus is being threatened, and experts believe many provinces will be unable to meet the future energy demands of heat waves. Although the country could rely on imported energy for the time being, the U.S. is also expected to have electricity shortages, meaning that purchasing energy from them may not be a viable solution.

So, what can be done to keep people safe without furthering climate change? There have been various propositions, and a combination of solutions will most likely be needed. One solution worth exploring is switching workers’ schedules from days to nights.

Read ahead to learn about the advantages and disadvantages of night shifts and whether they can be a viable solution to combat the effects of climate change.

What are the benefits of night shifts?

Even though nighttime temperatures are increasing at a faster rate than daytime temperatures, on average, nighttime temperatures are still much cooler.

Bhavesh Patel, a PhD candidate studying environmental science at the University of Toronto, explained that the main benefit of night shifts in climate change is that our bodies aren’t subjected to dangerous heat levels compared to during the day. This means we’re less likely to experience negative effects like heat exhaustion and heat stroke at night.

An additional benefit is that the sun will not be out, meaning there would be no harmful ultraviolet radiation and a decreased chance of skin cancer. This would be a clear benefit since ultraviolet radiation is expected to rise with climate change.

What are the hazards?

Though counterintuitive, Patel explained that nights during heat waves could be deadlier than days. This is because our bodies must sweat regardless of the time of day. However, our body’s natural cooling system can’t work correctly if the relative humidity is too high. This is because the air can only hold onto so much moisture at once, meaning relatively high humidity levels prevent sweat from evaporating from our bodies.

This can become deadly at night because there is no time for our bodies to recover from daytime heat. Patel said that 35 degrees Celsius at 75 per cent relative humidity is now considered the safe heat limit for humans. This is known as the wet-bulb temperature and is believed to be the temperature limit for human survivability. Patel explained that the wet-bulb temperature is dangerous because the humidex makes it feel like 40 C. This is above body temperature,  usually between 35 and 37 degrees. Because the ambient temperature in the wet bulb is hotter than our bodies need to run optimally, this can become dangerous, even to healthy people.

In other words, if the nighttime temperature is higher than the wet-bulb temperature, our bodies can’t use sleep to cool off. If the wet-bulb temperature is maintained both day and night, it is unsafe no matter what time of day.

Another consideration, according to Patel, is that night shifts would mean that workers are sleeping during daytime heat, which may be even more uncomfortable and potentially more dangerous.

On top of the negative health effects, Patel stressed that for this adaptation strategy to work, a night shift worker would need to have some way to cool their home down during sleep hours due to the wet-bulb temperature effect. This would mean that they could cool down fully during sleep hours.

Are night shifts the answer?

Patel said night shifts could be a good option for some people, depending on their circumstances. However, night shifts come with non-climate change-related negative consequences, including worse sleep and poor physical and mental health. Specifically, there are concerns about an increased risk of cancer, diabetes, metabolic disorders, gastrointestinal health problems, mood disorders and anxiety. This means that night shifts are not for everyone. But some people are hardwired to be night owls, so they may be perfectly content getting their work done at night.

Society needs strategies to mitigate the effects of climate change on humans, but this should not come at a cost to our health. Instead of working night shifts, a University of Oxford study suggested that 9-5 work could be adjusted to 6 a.m. to 2 p.m. to avoid the worst effects of daytime heat. This may be more appropriate for people who work better in daytime hours than night owls. Both people who adopt a 6-2 schedule and night shift workers who have a way to cool off during sleep hours might be able to live more comfortably and safely during heat waves.

More climate adaptation strategies will come in the future, so don’t worry if you’re one of the many who fall asleep at 9 p.m. Climate change is an immensely complex problem that we are still trying to understand, so there will certainly need to be multiple solutions rather than just a single one.