Tkinter root windows have a method called after which can be used to schedule a function to be called after a given period of time. So call that function itself like (you will have to create a class first):

def update_label(self):    self.label.configure(cpuTemp)    self.root.after(1000, self.update_label)

This will then reload your label every second.

This may help you: Creating a Timer with tkinter

TKINTER

Refresh, Update, Rerender

This code works for any type of Tkinter widget update

#!/usr/bin/env python3import sysimport timefrom tkinter import *# Global variablesrunning = True# Button action updaterdef callback():    if button_1["state"] == "disabled":        button_1["state"] = "normal"    else:        button_1["state"] = "disabled"        root.after(4000, callback)# Window setuproot = Tk()root.title("Buttons")root.geometry("400x300")# Buttons setupbutton_1 = Button(root, text="Learn Python", command=callback)button_1.pack()# Kills window without _tkinter.TclErrordef kill():    global running    running = False    sys.exit()# Software loopwhile running:    root.protocol("WM_DELETE_WINDOW", kill)    root.update()

Python version used to created this software is: >=3.x