Extreme weather events pose significant challenges for gig couriers, impacting their performance, income and health. Research with one food delivery platform in China showed that heat waves drive up order volumes for couriers, but also cause more delays and higher health costs. These couriers could end up working hard in heat for an entire summer and only make around $6 in extra money. Platform managers and policymakers should recognize the impact of extreme weather on gig economy and take preventive measures to meet user needs during heat waves, balancing operational efficiency with the health of the gig workers.

Extreme weather events from heat waves to hurricanes have been exacerbated by global warming. This is particularly bad news for outdoor workers like food delivery couriers. During extreme heat, couriers working for China’s Meituan, Spain’s Glovo, and India’s Swiggy rush to complete deliveries on time, struggling with delay penalties and significant health risks. What’s more, food couriers usually lack formal worker status, leaving them without essential labor protections.

Using data from one food delivery platform in China, we analyzed heat waves’ impact on gig couriers’ performance, income, and health. We observed that while heat waves drive up the order volume, they also result in more delays and disproportional health costs for these workers. Without proper intervention, this not only undermines couriers’ well-being but also erodes customer satisfaction and threatens the sustainable growth of delivery platforms.

Platform managers and policymakers should recognize the impact of extreme weather on gig economy and take preventive measures like optimizing the algorithms to meet both the needs of consumers and couriers. The goal is to balance operational efficiency with the health and safety of the gig workers who sustain these systems.

Understaffed Platforms and Overburdened Couriers

Food delivery platforms in China need to handle as many as 60 million orders every day. More than seven million delivery couriers are registered for this work. Such scale and complexity makes it very hard to quickly respond to surges in demand during a heat wave, forcing platforms to rely on existing food couriers to take on more orders and work longer hours in extreme heat.

We confirmed this hypothesis through our work with one food delivery platform in China, analyzing data from 2015 consisting of more than 580,000 orders and 1,272 gig couriers from two major Chinese cities, Shanghai and Hangzhou. This was a time when the on-demand food delivery industry was just beginning to gain traction in China. At that time, platforms primarily offered delivery services for a limited range of products, allowing us to focus on the delivery of food items during our research without the added complexity of multiple product types.

We found that, for the two hottest months (July and August), the average number of food orders per hour in each city increased as the temperature went up. A 5°C increase in temperature (9°F) led to 36 more orders each hour, corresponding to a 9.6% jump in the number of orders per hour. Then we used official heat indices from the U.S. National Weather Service to define a “heat wave,” which is when the temperature is considered “dangerous” or “extremely dangerous” for outdoor activities. We found that, when a heat wave was happening, the food couriers worked 6% longer than they did at normal temperatures. So, when customers no longer go to brick-and-mortar restaurants when it’s extremely hot outside and place more orders on food delivery platforms, the gig workers had to deal with the increased workload and getting exposed in dangerous temperatures for longer periods of time. 

Although it is challenging to isolate the impact of heat hazard on food delivery couriers from more recent data, given the increasingly competitive environments where gig workers deliver a variety of products, along with consumers’ heightened dependency on delivery apps and couriers’ longer working hours, we suggest that the observed effects could be even more significant.

How Demand Surges Cause Problems for Both Couriers and Platforms

What do these findings mean for gig workers dashing to deliver food under a scorching sun? Despite the high demand, food couriers do not earn extra income proportional to their workload in extreme heat. While couriers working during heat waves saw a 9.1% jump in orders per hour, they also experienced a 21.8% increase in delays, as the increased orders tended to be spread out across different locations with varying demands. This increase in order variability, together with heavier utilization of individual food couriers, leads to more delays. Because the food couriers were penalized for late deliveries, they only made 8.6% more money every hour during heat waves — that’s about 1 CNY, or half the market price of a bottled mineral water.

Moreover, driven by extended working hours and heat exposure, food couriers faced health risks that far exceeded any additional income they earn during heat waves. Based on previous medical research, we concluded that couriers’ health costs could rise by 501 CNY ($70.30 USD) during the two months we studied. However, given their frequent delivery tasks in high temperatures and the limited access to insurance, the actual health costs could be more substantial, with this possibly representing just the lower bound. Compare that number to the extra earnings individual gig workers made in the heat: about 545 CNY, or $76.50 USD (to calculate this number, we used the extra hourly income 1 CNY x 8.8 hours/day x 62 days over the two months). The extra earnings barely cover that lower bound of the estimated health costs, which already represents the best-case scenario, assuming couriers have access to health insurance. Without such insurance, out-of-pocket payments could reach 11,204 CNY over the same period — more than 20 times the extra money an individual gig worker made in the heat.

These hidden health risks are often overlooked by gig workers, who are more likely to take on work during heat waves, as the prospect of immediate income is greater. In the long run, however, this could affect couriers’ engagement and well-being, leading to absenteeism and turnover that further challenge platform operations.

During extreme hot weather, increased demand can also mean increased order variability, which results in longer waiting times and more frequent delays. For example, our research indicated that the likelihood of delivery delays in Shanghai and Hangzhou increased almost 4 points when temperatures hit 35°C (95°F), reaching more than 1 delay in every 4 orders. The rate was less than 1 in 5 during milder conditions around 20°C (68°F).

Ultimately, it’s the platforms that have to pay in the end: Gig workers’ performance and delivery delays during heat waves can hurt customer satisfaction and affect future demand.

Implementing Better Strategies in Extreme Weather Events

Understanding these patterns is the first step: If platforms recognize how extreme heat impacts its delivery services, they could work to optimize route planning when a heat wave hits or deploy more experienced couriers who are familiar with the local environment and delivery process to reduce waiting time and control burdens on the average couriers.

In terms of route planning, the platforms could focus on adjusting algorithms to help gig couriers who have worked extended hours in the heat, prioritize routes that have more shaded areas or rest spots where they can replenish with essentials like water and food, provide protections or incentives in order to improve working conditions and performance, and remind couriers to take precautions against heatstroke. In addition, having more experienced couriers can achieve shorter delivery times, which can enhance the overall performance of the platform’s delivery service, making customers more inclined to use this food delivery service frequently.

For example, in China, Meituan set up mobile vans in high-risk cities like Shanghai, offering iced drinks, sunscreen, and raincoats to couriers. The Shanghai government has also established over 10,000 service stations to provide relief to couriers during heat waves. In New York City, Grubhub has partnered with e-bike rental platform JOCO to create indoor rest areas for couriers. They also provide gig workers with access to occupational accident insurance and an app called RapidSOS, which helps by sending location data in extreme weather emergencies during 911 calls. And in India, Zomato launched the Shelter Project, constructing rest spots with clean water, first aid, and other amenities for delivery agents.

Besides providing protections for gig couriers during heatwaves, platforms and governments need to come up with well-thought-through changes at the policy level, too. There’s mixed progress in this area. In 2022, Vietnam’s Grab App made an attempt to introduce a heat wave surcharge, but cancelled it later following concerns from a consumer watchdog. On the positive side, Singapore plans to put the Platform Workers Bill in place by 2025, which aims to offer work injury compensation and union-like representation.

In both domains — company-level and policy protections — more research will be needed to assess their effectiveness and broader impact on worker well-being, as well as the efficacy of their enforcement.