No, it depends on the setup and also the temps in your house. In my RBI rack I have my herpstat set at like 108 to get 88-90 temps, on my Johnsons on my DIY rack it's set to 98 to get 88-92 temps. In the winter I may need to bump it up slightly since my apartment is kept at about 68-70. It may be easier (and safer) to use a heater to heat the room they are in, or keep your temps up slightly higher in your house than you normally would...