2009 Prius Cargo Area floor is hot to the touch after 1 hour of running errands

I ran errands around town for about an hour (stop and go, not highway) and when I opened the hatch at home the cargo area floor was hot to the touch. I have had the car 9 1/2 years and have never noticed heat before. Is this normal?

Sorry to ask such a stupid question but I do not drive the car much and might just not have noticed this before.

 

The deck cover in the middle was very warm to the touch and transferred a similar amount of heat to an all metal floor fan I just bought. I think the whole deck cover was warm but did not really check. I probably would not have noticed the heat if the metal fan was not warm (hot, or whatever) and if the box the fan came in fit the cargo area I might not have noticed at all.

I did not remove the deck cover yesterday. My brain wasn't engaged until I had time to think about it. I put oven thermometers (lowest temp they report is 100 F) in the spare tire area and under the deck cover. *Today* I ran an errand (highway speed) and checked the thermometers both of which were not reporting a temperature and the hybrid battery was maybe slightly warm but just the smallest amount.

I looked up the 12 volt battery in the owner's manual which seems to say it is in the spare tire area. I probably did notice it today but not really see it for what it is, if that makes sense. What I know about this car could dance on the head of a pin.

Thank you

I have a cover and use it.

 

Today I put oven thermometers (lowest temp they report is 100 F) in the spare tire area and under the deck cover and at highway speeds nothing reported on the thermometers. Tomorrow I will try to reproduce yesterday's slow, hot trip letting the car spend 30 quality minutes in a very hot parking lot and see what the thermometers say. I used some science to figure out what 120 degrees feels like to the touch (outside of a Pyrex bowl of water) and think the deck cover pad was at least 120 degrees so the innards below that were probably hotter. I hope tomorrow to know more.

Does "battery cooling fan, intake grille" refer to the hybrid battery? The hybrid battery was checked about two weeks ago and was reported to be in very good condition. I have not looked at the intake grill for the hybrid other than to make sure nothing was blocking it and have to assume the shop looked at the fan as well as the battery itself. I have not looked at the 12 volt battery but will look at it tomorrow. It is a Toyota OEM battery and is 3 1/2 years old. I have maintained this car very well and it has less than 12K miles on it over the 9 1/2 years I have owned it.

Thank you

 

Yesterday was 70(ish) and right now the temp is 73 degrees. The car was in a parking lot for maybe 30 minutes and was not particularly warm inside when I came out. The cargo area did not seem much warmer than the rest of the car when I rolled back the cargo area cover and put the metal fan in. I would have noticed if the car was very warm because I put my dog in first. Dog then fan.

I am certain yesterday the cargo area floor was hot (warm) to the touch and radiating heat when I got home and removed the metal fan. (I really do not have a clue what the floor was doing when I put the fan in.) Heat transferred from the floor to the fan on the drive home (2 miles) on slow stop and go surface streets. The fan was much hotter than ambient and several cardboard boxes in the cargo area. I think that makes sense.

I have 2 oven thermometers in the car (0 in my oven) which I will check and recheck every time I remember to check and recheck them. I will update this thread with relevant information.

If anyone has a Prius and has seen anything similar please share or keep asking questions. A light bulb somewhere might click on!

Thank you

 

Thank you

 

"might be [warm] spots on the floor of the passenger compartment" I only noticed heat radiating from the cargo area floor because the metal object on it was warm to the touch. I would never notice a warm spot on the floor of the passenger compartment. I will try to notice such things. It's also probably a good bet that the muffler on a 9 1/2 year old car with only 12 K miles has not been looked at.

I will have both the muffler and hybrid (?) battery cooling system checked.

Don't know what I can do about worrying...

Thank you