Chelsea have been warned of the dangers of playing in scorching 39C heat on Tuesday night — with the city of Philadelphia declaring a ‘Heat Health Emergency’ ahead of the Londoners’ next Club World Cup clash.

Enzo Maresca’s side are using Philly as their training base and will face the Tunisian club ES Tunis in their final group game at the Philadelphia Eagles’ Lincoln Financial Field, when local  temperatures in Pennsylvania’s largest city are forecast to soar.

Juventus will face Wydad of Morocco at the same stadium at noon today, which is when Philadelphia’s emergency will officially kick in.

FIFA told Mail Sport yesterday that their medical experts are contacting their counterparts at Club World Cup sides regarding the rising heat and humidity, and that their top priority is the safety of everyone involved.

Maresca has had to adapt to the temperatures by limiting the minutes he hands to Chelsea players with histories of muscular issues, such as Reece James and Romeo Lavia. The squad were having a rest day yesterday, with the Blues trying to manage workloads.

Chelsea have been warned of the dangers of playing in scorching 39C heat on Tuesday night

Chelsea are using Philly as their training base and will face the ES Tunis in the final group game

Maresca has had to adapt to the temperatures by limiting the minutes he hands to  players

Whereas Chelsea’s win over Los Angeles FC was held at Atlanta’s Mercedes-Benz Stadium — where the closed roof and big air-con units made it feel like football in a fridge — the Lincoln Financial Field is an open arena. Both venues will be used for the 2026 World Cup, and that will also take place at the height of summer in the United States.

England manager Thomas Tuchel is currently in the US, and was in Miami on Friday to see Bayern Munich beat Boca Juniors 2-1, with Harry Kane scoring the opener. FA insiders say Tuchel is more concerned with visiting facilities and training bases than assessing how players cope with the scorching weather.

Kane, speaking after Bayern’s win, said England’s players will benefit from getting an early taste of the climate. ‘You have to be able to adapt,’ he said. ‘It’s a great experience for me and some of the other England guys who are playing this year and who will be playing next summer.

‘There’s always something special about these World Cup games and next year will be the same. When you come off that pitch and you’re dripping and you’re cramping and you’ve given everything out there, there’s a special feeling inside, especially when you win.

‘We (the England players) are not in touch with each other right now but it’s something we’ll talk about at upcoming camps — how we adapted to it and what training methods we used.

‘All of this is good experience because it’s going to be tough next summer, without a doubt. And we must use our experiences as an advantage.’

Kane and Tuchel will have noted that the South American sides dealt with the heat better than their European counterparts. Botafogo beat Paris Saint-Germain and Flamengo overcame Chelsea at this Club World Cup.

The Lincoln Financial Field is an open arena and there is no air-con when temperatures hit 39C

Flamengo manager and ex-Chelsea star Filipe Luis said his team are more used to the climate

Players will be advised to ‘avoid, as much as possible, working or playing in the hot sun’

Kane said England’s players will benefit from getting a taste of the heat before the World Cup

Flamengo manager Filipe Luis, the former Chelsea left back, admitted that his players are more used to this climate. ‘Sometimes, the weather, they’re not used to this,’ Luis said of European sides. ‘But the South American clubs are very competitive and not always the best win the Copa Libertadores. There’s different grass, altitudes, so we have a lot of adaptations and we are used to that.’

The Philadelphia authorities have set up a ‘Heatline’ so those in need can phone for help, with cooling centres and home visits by special field teams. The Office of Homeless Services also declared a ‘Code Red’. Locals are being encouraged to check in on loved ones.

FIFA told Mail Sport: ‘FIFA’s top priority is the health of everyone involved in football, and FIFA’s medical experts have been in regular contact with the clubs participating in the FIFA Club World Cup 2025 to address heat management and acclimatisation.

‘FIFA has also deployed medical officers who work closely with the local medical authorities to address key health matters, including heat management.

‘As successfully applied at previous tournaments and as referenced in the FIFA Club World Cup 2025 Regulations, FIFA is implementing a sound preventative concept at all venues, including cooling breaks in the 30th and 75th minutes, in accordance with protocols.’