As Europe braces for another heatwave, one group of workers has little choice but to sweat it out: the couriers shuttling around town getting lunches and dinners to customers.

"It's hot, sometimes really hot. But what can we do? God is in charge of the weather," says Gennaro Guarracino, 47, who delivers food by scooter around the Italian city of Naples for the company Glovo.

Temperatures were expected to reach 34-38 degrees (93-100 degrees Fahrenheit) across Western Europe on Thursday.

But labour practices such as offering workers cold water, shade and extra paid breaks are not universally adopted or enforced, with the meals delivery market a prominent example because many of its workers are on freelance contracts.

In July the mayor of Palermo on the Italian island of Sicily signed an order that horses carrying tourists be given at least 10 litres of water per day and that tours be halted when temperatures rise above 37 degrees Celsius (98.6 Fahrenheit).

With support of a labour union, bicycle courier Gaetano Russo, who also delivers food for Glovo, filed a suit demanding similar treatment.

"Am I worth less than a horse?" Russo was quoted as saying in a statement of Italian union Nidil CGIL, which represents workers on flexible contracts.

Following the complaint, on Aug. 3 a judge ordered that the rider be given an insulated bottle for cold water, electrolytes and sunscreen.

Among European meals companies Glovo, Uber and Deliveroo follow a model where couriers are considered self-employed. Just Eat Takeaway, the largest, employs its own couriers in most markets.

In a response to questions from Reuters, Glovo parent Delivery Hero said its "riders have the freedom to choose their shifts, can request a break at any time, and receive appropriate equipment for the season."

Labour experts say that accidents become more frequent on hot days, while scientists warn that extremely warm days that increase risk of heat stroke are becoming more common due to global warming.

The dangers posed by working on hot days were underlined by the heat stroke death of a Madrid street sweeper during the continent's July heatwave.

That prompted renewed calls by the European Trade Union Confederation to set a maximum working temperature - none currently exists.

"It's surprising how few nations have rules," said Juanita Constible of the Natural Resources Defense Council (NRDC), an international environmental advocacy group. "I'm hopeful that as countries are grappling with what it means to live in a warmer world, they'll pay more attention to what workers need."

Spokespeople for Uber and Deliveroo said they relay government weather advisories to their contractors.

Critics of the self-employment model, including NRDC's Constible, say many workers can't afford to take breaks and are putting themselves in danger by staying on the job.

"No one should die to deliver food to someone on a hot summer day," she said.

In December, the European Commission announced draft rules that would classify most gig workers as employees, but that plan has yet to become law.

"For me personally I just take it easy, watch how much I'm sweating," said Edward James Morta, a courier for Takeaway in the Dutch city of Utrecht, who is on a regular contract including paid breaks.

"I do bring a lot of water with me," he said.