Cornell University Ergonomics Web

Hot laptops cause problems for users

Hot Crashes!

Modern laptops run fast microprocessors that can generate a lot of heat. The heat is mainly vented out of the bottom of the laptop but ventilation effectiveness is reduced when the laptop is placed on a solid surface or on your lap. A hot laptop can suffer from reliability problems and a system that overheats can fail. [1]. The accumulation of heat can crash your laptop processor.  Heat can also crash your laptop hard drive. Hard disk drives can overheat and crash, causing you to lose valuable data! Manufacturers recommend normal working temperature of 95-104F (35-40С). At temperatures from 104-122F (40-50С) you double the chance of a hard drive crash!

Hot thighs!

A hot laptop can be uncomfortable to use in your lap. The heat from some laptops can be enough to cause superficial skin burns, even through clothing! The Lancet medical journal reports the case of a healthy 50-year old scientist, fully dressed in trousers and underpants, who burned his genital area after placing his laptop on his lap for an hour. While using the laptop he did occasionally feel the heat and a burning feeling on his lap and proximal thigh. Two days later he had blisters that burst and developed into infected wounds. [2]

In addition to a hot laptop being uncomfortable to use, if you are a man, it may reduce your fertility. [3] A recent research study of 29 healthy male volunteers measured right and left scrotal temperature in every 3 minutes in two separate 60 min sessions: sitting and working with and without the laptop on the thighs. With the laptop in the lap, skin temperature was significantly higher (P<0.0001). The researchers concluded that working with a laptop positioned on the thighs causes significant elevation of skin temperature in the groin as a result of heat exposure and posture-related effects. Long-term exposure to repetitive hot laptop use in the lap may have a negative impact upon fertility, specifically in teenage boys and young men.

  1. Consumer Reports, March 2003 , Laptop Computer Test- "Portable power" pp 44-47
  2. Ostenson, C. G. (2002). "Lap burn due to laptop computer." Lancet 360(9346): 1704.
  3. Sheynkin ,Y., Jung, M., Yoo, P., Schulsinger, D. and Komaroff, E. (2005) Increase in scrotal temperature in laptop computer users, Hum Reprod., 20 (2) 452-5.


A growing number of products, such as laptop stands, trays and attachments like LapTraxx, can be used to alleviate these problems.

Hit Counter people have visited this page.


Note that all materials on this page and web site are copyright and may only be copied or distributed for nonprofit educational purposes without permission.
© Alan Hedge, page content last revised on
December 08, 2005