Thermotolerance is a living organism resistance to temperatures causing death in normal conditions.

David Charles Martin has written:

'Heat- and cold-shock induced changes in gene expression and thermotolerance in corn, Zea mays L'

Richard Jason Kirby has written:

'Photosynthetic activity and acquired thermotolerance in the cyanobacterium, Anabaena sp. PCC7120' -- subject(s): Cyanobacteria, Effect of temperature on, Effect of light on, Anabaena

Genotype is the particular alleles at specified loci present in an organism. Genotype effects on body temperature in dairy cows under grazing conditions in a hot climate including evidence for heterosis. Its reflect two effects. First, Swedish Red Holstein had higher vaginal temperatures than the other genotypes in the late morning and afternoon but not after the evening milking. Secondly, Jersey Holstein had lower vaginal temperatures than other genotypes in the late morning and afternoon and again in the late night and early morning. Results point out that there are effects of specific genotypes and evidence for heterosis on regulation of body temperature of lactating cows maintained under grazing conditions and suggest that genetic improvement for thermotolerance through breed choice or genetic selection is possible.