Heating element

Hi folks , i got one cabinet with hps 100 W ,temp when lamp is on is ok , but at night it goes to low , what is the lower value of the temp at night in flower period?
And what kind of heating emitter should i use to keep temp at night?
i found either heating mat or terarium ceramic emitter, what you think which one will work or be the best?

Your temps can drop into the low 60s upper 50s with lights off. If you need a heat emitter i'd go with a matt as heat rises and it will keep your soil warm

Yes probably i will go with matt , couse ceramic heat emitter could hurt plants i hope that temps will not go below thanks