Heat liquids (water, milk) to specific temperature?

I was wondering if there's a device (to buy, or make if it's a relatively simple DIY) that can heat liquids to specific temperatures.

Baking breads and other things, often you need water/milk at a specific-ish temp. Currently I'm using a kettle or stovetop and then a thermometer to gauge where the temperature is. Often i overshoot so have to wait for cooling...so I was just wondering if that's the best/most practical way, or if there's some device/thing I can set a temp and then let it heat up the liquid for me.

Edit: main temp range is 50°-90° or so Farenheit

It's easy to ratio known quantities at two known temperatures e.g. 2:1 room temp:boiling gives about 47°C (so 2:1 fridge or tap cold to boiling is good for bread)

Two devices come to mind: (a) an immersion circulator (commonly known as a sous vide stick or device), and (b) the Breville Control Freak induction burner. The first can be had for as little as $50 US. The Control Freak sells for about $1500 US. You can directly heat water with the immersion circulator. Other liquids would have to be heated in a bag. Both are very accurate.

You can probably DIY something with a PID, an electric or induction burner, and a thermocouple.

...and as Chris H points out in a comment, there are some electric kettles (like this one, for example) with temperature control.

You can buy laboratory hot-plates (frequently hot-plate with magnetic stirrer as well, which helps keep the temperature even) that have temperature control to fairly precise levels, usually "crude" by lab standards without a probe (sensing from the plate) and "good" with a probe that goes in the liquid. Crude is likely good enough for most kitchen use.

I happened to stumble onto them when I was looking for a 5" hot plate to suit some particularly small pots I have.

You can surely get a single-purpose device that will turn off at the right moment, but I wouldn't see this as a practical solution. Especially not a kettle - they are imprecise, don't go to low enough temperatures for baking ingredients, and can't be used for anything but water.

As moscafj noted, an immersion sous vide might be the closest you can get. But then you have to contend with a minimum amount of liquid needed, not being usable for solid stuff like butter or soaked gelatine (unless you play with bags), and additional cleaning effort.

Personally, I'd either get a thermometer with an alarm function, or just be more disciplined about monitoring a simple thermometer myself. Especially if you're warming small quantities, and want temperatures in a low range (such as having your water at 35 C for shorter rising times for a yeast dough) it is really a very quick thing, and beats the hassle of having extra gear.