Lewis Hamilton is concerned Mercedes' overheating issues could come back to haunt the team at the German Grand Prix.
Mercedes had issues during hot conditions in Austria in June, with engine overheating limiting the modes available to Hamilton and his team-mate Valtteri Bottas.
Following the Austrian Grand Prix, Mercedes confirmed they were working to find a solution, and incorporated cooling changes as part of the team's upgrade package for the upcoming race at Hockenheim.
However, Hamilton is uncertain the issue has been resolved, and is praying for wet, cooler conditions, with rain expected to arrive in Germany over the weekend.
"It is definitely a good thing if it rains. There is not much we can do, it is a much bigger design issue when it gets hot which is not so easy to change," Hamilton said.
"We are working towards it, but it is very small steps and small increments which are not making a massive difference.
"But hopefully this weekend it will be okay in that sense, but if it stays this hot we are going to struggle and be in trouble.
"If the next race is this hot we are going to be in trouble and on the edge as we were in Austria but fingers crossed the weather comes in."
Hamilton sits top of the Formula One drivers' standings, holding a 39-point lead over team-mate Bottas, with Max Verstappen of Red Bull in third place after 10 races.Published 26 Jul 2019, 04:06 IST