Can I put a cover over my hot plate?

Yes, but there are some conditions.

Fitting an after-market cover over a cooking appliance burner makes the appliance into a stowed appliance.

A stowed appliance must have a means to stop the flow of gas to the appliance when the lid is closed. This can be achieved by using an additional cover over the appliance’s own cover where the appliance is fitted with a flame safeguard system that cuts off the gas flow when the cover is closed. If this is not already present on the appliance, a separate gas interlock system must be designed into any after-market cover (see Clause 6.3.2).