Clerks of the course at the two feature meetings on Saturday are expecting a "challenging" few days.
While Ascot and Haydock were both raceable on Tuesday, temperatures are set to drop dramatically in the run-up to the weekend.
Frost plus the prospect of some snow could threaten both Ascot, where Sprinter Sacre would be the headline act in the Victor Chandler Chase, and Haydock, where the Peter Marsh Chase is the centrepiece.
Ascot report no problems so far with the going described as soft, good to soft in places.
Clerk of the course Chris Stickels said: "Weather conditions haven't been as severe as forecast, but temperatures are forecast to be colder. There is a threat and the forecast does look a little bit challenging. We have had frost covers down since last Saturday. We are well prepared in anticipation of this."
Haydock, where the going is heavy, have also taken the necessary precautions.
Clerk of the course Kirkland Tellwright said: "We are covered up. It's been so far so good and we were fit to race (on Tuesday) after it got down to minus 2C.
"The next couple of nights look like a bigger test as we might get down to minus 8C or minus 9C. Covered or not, that will be a fair challenge. All we can do is take it one step at a time."
Looking further ahead, Cheltenham have deployed frost covers on the chase and hurdles courses for Festival Trials Day on Saturday week.
Head of racing Simon Claisse said: "The current forecast is for temperatures to remain cold for the remainder of this week, with some very hard frosts. In view of this, we have put down frost covers on the chase and hurdle courses in order to give Festival Trials Day every chance of going ahead."
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