You should have a heater in a Tropical tank weather its hot in the house or not as when night fall comes the tank cools back down possibly dropping a big number of degrees throughout the night and reheating during the day, the heater should be set a couple degrees lower than that of your homes ambient temperature so there's not a huge drop at night time) heater won't come in during the day) , In the cold months you just slowly lower the heater back down around the ambient temp of the house you have the home set at, but right now I would get kordon Rid ich plus, DO NOT ADD SALT with it, dose the tank per instructions, if you have scale less fish it's a whole different thing with treatment so if you have scaless fish don't add meds that are unsafe for them (rid ich plus is not scaless fish safe).
Also the tank isn't cycled I'm assuming as you got it 2 days ago so that's most likely how you got ich a combination of an unestablished tank and new fish = issues, you will have to do water changes daily with the rid ich but if you have a filter with a cartridge you have to remove the carbon from the cartridge or the med won't work) to do this cut a slit in the bottom Of the cartridge material and empty out the black Rock (that's carbon) , after you see no more fish with spots you treat for an additional 3-5 days (i do anyways), also with the tank not being established after you clear up the ich you need to do daily water changes with new water treated with seachem prime (if you can get it) so your tank doesn't get out off control with the water parameters and so that they stay healthy while you do a fish in cycle, there's posts on this forum of how to do them.