The quickest and cheapest method that's really effective is a fan blowing over the water surface.
I brought down my Clown loach tank from 89.6 to 86.5 the other day just by taking the lid off the Aquaclear 500 HOB and aiming the fan at it. Lost about 5 gallons in 24 hours due to evapouration mind you, but that's why it works so effectively.
if you have an old compact freezer you can make a cheapo DIY freezer. just drill holes in the freezer top and run some tubing through it so you can pump water from the tank through the cold freezer. this does take some math skills because you need to know how long to expose the water to the cold air and what the flow rate should be. and now that ive just typed this up im realizing that this is a ridiculous amount of overkill for your situation. but i always thought it was a neat DIY job to attempt. made one for my reef tank once.
CLI.. What size tank and what type of fish? Treated ice cubes work great because you loose water due to evaporation and the cubes cool the tank and replace evaporated water.. A glass "IN"tank thermo is normally fine those sticky ones are horrible dont know y they even sell them(just my opinion)
Good luck
Do they have a fast readout too? I'm asking you this, because the main reason I hate water changes is not the water change itself, but getting the temperature right. The digital thermometer I have shows a new readout every 5 seconds and that drives me nuts, because I keep correcting water temperature over and over (I'm picky about having the correct water temperature and so are some of my fish).