I agree with sparky although the uart interrupt is cleared once the register is read.
There are several uart examples with interrupt in this forum. Start with those and modify to suit your needs.

You need to verify the registers are correct for whatever chip you use. PIE1.RCIE=1; //enable receive interrupt INTCON.PEIE = 1; INTCON.GIE = 1; as well as LATB.F0 = ~LATB.F0; // indicates if no error in data transfer since some chips do not use LAT.xx but otherwise it should work. Just try it, the ...

Have you looked at the examples? You can make slight modifications and get the results you are looking for and learn different programming strategies in the process. It is how I learned.
Break it up into individual parts. Button, timer, display, done.

No, but we would be glad to help correct your attempt at the code. Start with the mE examples. Turn on a lite for a few hundred milliseconds then turn it off and another on and so on. When you get to the end, reverse the sequence. There are multiple ways of doing this sequencing and working through ...

You seem to be assigning a float value to a char with extended_temperature.
I am a little rusty with my coding though.

Have you tried inttostr() found in help file?

Take a series of readings and average them. About 30 should be fine. Ill try to post some code later but no need to wait for me to try it out.
Btw "Dougs" are awesome.

Are the fuse settings the same for each?

And use LCD_Chr_Cp() so you can increment on the LCD and not write over the previous text.

You are writing the unsigned short in the same place on the LCD. I think you want to store all your received values in an array and then write it to the LCD.
also you could increment the LCD using LCD_Chr or similar.

Have you used the PC as both a transmitter and receiver for testing?
On the PICs you have TX from one going to RX of other?
Are the grounds connected from both PICs? This is a common mistake.

If it is running hot it could also be a current issue. What is your current draw?

I think we might need to see more code.
Also, can you explain again the problem?

I would bet that noise is the problem. Do you have a regulated power supply and caps especially a 0.1 and maybe even a 0.01uF filter cap next to the VDD/VSS? I use the mE terminal program. Easy to access and full of features. What device/voltage are you sampling? Sometimes that can make a difference...

Google translate says "gia tri truyen" is "values" in Vietnamese.