Cold shock at temperatures below 11C was previously believed to delay cotton development. This paper tested whether exposure to 10C for 10 and 20 nights affected tissue viability. Experiments were conducted using plants grown in the glasshouse at the 14-node stage and plants grown outdoors at the 7-node stage. Simple tissue viability tests using tetrazolium (TTC) and relative electrical conductivity (REC) were conducted following treatments. Leaf photosynthesis and chlorophyll fluorescence were also measured to determine whether there were changes in photosynthetic function. Plants treated with cold shock at 10 'C for 10 and 20 nights did not show any significant impact on tissue viability or cell membrane integrity in the TTC and REC tests, respectively. Photosynthesis and chlorophyll fluorescence levels fell slightly in the 20 night treatment compared to the control, but recovered quickly outdoors at the end of the 20 nights. There was no evidence in the data that exposure to 10C for 10 and 20 nights will reduce cotton tissue viability or plant growth.