Continuously changing values in the same band of a multiband raster

I am having issues with continuously changing the values of pixels within a single band of a multiband raster using python 2.7. Essentially, what I am trying to do is continuously change (increment) the pixel values of a single band based on variables drawn from 2 lists that are used in the nested loop. I've included some code to help understand what I'm doing.

import arcpy
import os
from arcpy.sa import *
import math

arcpy.CheckOutExtension('spatial')

ConstantList = [2.1, 1.6]
TimeStep = ["4h", "8h", "12h", "16h", "20h", "24h"]

multiband = "Path:\\to\\my\\multibandraster.tif\\"

arcpy.env.workspace = multiband

bands = [Raster(os.path.join(multiband, b)) for b in arcpy.ListRasters()]
count = 1
for constant in ConstantList:
for time in TimeStep:
temperature = Raster("Path:\\to\\temperatureRasters\\" + time + "_1_1971.tif"

bands[1] = Con(((temperature > 2.5) & (temperature < 35)), bands[1] + some equation, bands[1])

bands[1].save("Path:\\to\\output" + str(count) + ".tif")
count = count + 1

arcpy.CheckInExtension('spatial')


Using this code, I get a raster with all pixels = NoData. If I remove the 'time' for loop (for time in TimeStep:....) I can get the correct values, but only for one timestep. Why would including the 'time' for loop give me a raster with NoData, and how can I fix it?

Also, I should mention that when I remove the 'time' for loop, the values of bands[1] during the execution of the second constant in the constant list, are wrongly added to bands[1] values calculated during the execution of the first constant. At the start of the second constant, the values of bands[1] should be reset to the original values of the multiband raster.